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 A064907 Semiprimes p1*p2 such that p2 mod p1 = 9. 1
 341, 583, 731, 793, 893, 1067, 1469, 1793, 1807, 1943, 2201, 2323, 2483, 2519, 2761, 3043, 3071, 3487, 3497, 3781, 4213, 4439, 4511, 4777, 4841, 4849, 4939, 5497, 5809, 5933, 5947, 6511, 6539, 6989, 7093, 7117, 7391, 7493, 7601, 7613, 7783, 7891, 7967 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS John Cerkan, Table of n, a(n) for n = 1..10000 MATHEMATICA spQ[n_]:=Module[{fi=FactorInteger[n][[All, 1]]}, PrimeOmega[n]==2&&Mod[ fi[[2]], fi[[1]]]==9]; Select[Range[8000], spQ]//Quiet (* Harvey P. Dale, Aug 02 2019 *) PROG (Python) from sympy import factorint def is_A064907(n):     f = factorint(n)     return (sum([f[i] for i in f]) == 2) and (max(f) % min(f) == 9) def list_A064907(cnt):     inx = 0     n = 1     an = []     while inx < cnt:         if is_A064907(n):             an.append(n)             inx += 1         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]) == 9); \\ Michel Marcus, Apr 16 2018 CROSSREFS Cf. A001358 (p2 mod p1 = 0), A064899-A064911. Sequence in context: A006970 A007324 A007011 * A043685 A043576 A215326 Adjacent sequences:  A064904 A064905 A064906 * A064908 A064909 A064910 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 August 17 17:25 EDT 2019. Contains 326059 sequences. (Running on oeis4.)