SELECT count(distinct c) as nb FROM t_asv where b = 13 group by b
1 Adam, Seth, Enosh, 2 Kenan, Mahalalel, Jared, 3 Enoch, Methuselah, Lamech, 4 Noah, Shem, Ham, and Japheth. 5 The sons of Japheth: Gomer, and Magog, and Madai, and Javan, and Tubal, and Meshech, and Tiras. 6 And the sons of Gomer: Ashkenaz, and Diphath, and Togarmah. 7 And the sons of Javan: Elishah, and Tarshish, Kittim, and Rodanim. 8 The sons of Ham: Cush, and Mizraim, Put, and Canaan. 9 And the sons of Cush: Seba, and Havilah, and Sabta, and Raama, and Sabteca. And the sons of Raamah: Sheba, and Dedan. 10 And Cush begat Nimrod; he began to be a mighty one in the earth. 11 And Mizraim begat Ludim, and Anamim, and Lehabim, and Naphtuhim, 12 and Pathrusim, and Casluhim (from whence came the Philistines), and Caphtorim. 13 And Canaan begat Sidon his first-born, and Heth, 14 and the Jebusite, and the Amorite, and the Girgashite, 15 and the Hivite, and the Arkite, and the Sinite, 16 and the Arvadite, and the Zemarite, and the Hamathite. 17 The sons of Shem: Elam, and Asshur, and Arpachshad, and Lud, and Aram, and Uz, and Hul, and Gether, and Meshech. 18 And Arpachshad begat Shelah, and Shelah begat Eber. 19 And unto Eber were born two sons: the name of the one was Peleg; for in his days the earth was divided; and his brother's name was Joktan. 20 And Joktan begat Almodad, and Sheleph, and Hazarmaveth, and Jerah, 21 and Hadoram, and Uzal, and Diklah, 22 and Ebal, and Abimael, and Sheba, 23 and Ophir, and Havilah, and Jobab. All these were the sons of Joktan. 24 Shem, Arpachshad, Shelah, 25 Eber, Peleg, Reu, 26 Serug, Nahor, Terah, 27 Abram (the same is Abraham). 28 The sons of Abraham: Isaac, and Ishmael. 29 These are their generations: the first-born of Ishmael, Nebaioth; then Kedar, and Adbeel, and Mibsam, 30 Mishma, and Dumah, Massa, Hadad, and Tema, 31 Jetur, Naphish, and Kedemah. These are the sons of Ishmael. 32 And the sons of Keturah, Abraham's concubine: she bare Zimran, and Jokshan, and Medan, and Midian, and Ishbak, and Shuah. And the sons of Jokshan: Sheba, and Dedan. 33 And the sons of Midian: Ephah, and Epher, and Hanoch, and Abida, and Eldaah. All these were the sons of Keturah. 34 And Abraham begat Isaac. The sons of Isaac: Esau, and Israel. 35 The sons of Esau: Eliphaz, Reuel, and Jeush, and Jalam, and Korah. 36 The sons of Eliphaz: Teman, and Omar, Zephi, and Gatam, Kenaz, and Timna, and Amalek. 37 The sons of Reuel: Nahath, Zerah, Shammah, and Mizzah. 38 And the sons of Seir: Lotan, and Shobal, and Zibeon, and Anah, and Dishon, and Ezer, and Dishan. 39 And the sons of Lotan: Hori, and Homam; and Timna was Lotan's sister. 40 The sons of Shobal: Alian, and Manahath, and Ebal, Shephi, and Onam. And the sons of Zibeon: Aiah, and Anah. 41 The sons of Anah: Dishon. And the sons of Dishon: Hamran, and Eshban, and Ithran, and Cheran. 42 The sons of Ezer: Bilhan, and Zaavan, Jaakan. The sons of Dishan: Uz, and Aran. 43 Now these are the kings that reigned in the land of Edom, before there resigned any king over the children of Israel: Bela the son of Beor; and the name of his city was Dinhabah. 44 And Bela died, and Jobab the son of Zerah of Bozrah reigned in his stead. 45 And Jobab died, and Husham of the land of the Temanites reigned in his stead. 46 And Husham died, and Hadad the son of Bedad, who smote Midian in the field of Moab, reigned in his stead; and the name of his city was Avith. 47 And Hadad died, and Samlah of Masrekah reigned in his stead. 48 And Samlah died, and Shaul of Rehoboth by the River reigned in his stead. 49 And Shaul died, and Baal-hanan the son of Achbor reigned in his stead. 50 And Baal-hanan died, and Hadad reigned in his stead; and the name of his city was Pai: and his wife's name was Mehetabel, the daughter of Matred, the daughter of Me-zahab. 51 And Hadad died. And the chiefs of Edom were: chief Timna, chief Aliah, chief Jetheth, 52 chief Oholibamah, chief Elah, chief Pinon, 53 chief Kenaz, chief Teman, chief Mibzar, 54 chief Magdiel, chief Iram. These are the chiefs of Edom.