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 A064902 Semiprimes p1*p2 such that p2 mod p1 = 4, with p2 > p1. 1
 77, 95, 145, 221, 295, 371, 395, 407, 437, 445, 469, 545, 559, 649, 695, 745, 763, 895, 959, 995, 1057, 1133, 1145, 1159, 1195, 1253, 1345, 1351, 1513, 1517, 1679, 1745, 1795, 1841, 1895, 1939, 1945, 2021, 2045, 2095, 2101, 2195, 2245, 2249, 2395, 2429 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS John Cerkan, Table of n, a(n) for n = 1..10000 PROG (Python) from sympy import factorint def is_A064902(n):     f = factorint(n)     return (sum([f[i] for i in f]) == 2) and (max(f) % min(f) == 4) def first_A064902(n):     x = 1     an = []     while len(an) < n:         if is_A064902(x):an.append(x)         n += 2     return an # John Cerkan, Apr 14 2018 (PARI) isok(n) = my(f = factor(n)); (#f~ == 2) && (vecmax(f[, 2]) < 2) && ((f[2, 1] % f[1, 1]) == 4); \\ Michel Marcus, Apr 16 2018 CROSSREFS Cf. A001358 (p2 mod p1 = 0), A064899-A064911. Sequence in context: A274172 A061671 A269809 * A247682 A127335 A193570 Adjacent sequences:  A064899 A064900 A064901 * A064903 A064904 A064905 KEYWORD nonn AUTHOR Patrick De Geest, Oct 13 2001 EXTENSIONS Offset changed by John Cerkan, Apr 12 2018 STATUS approved

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Last modified June 12 19:57 EDT 2021. Contains 344962 sequences. (Running on oeis4.)