A064909 Semiprimes p1*p2 such that p2 > p1 and p2 mod p1 = 11.

481, 1157, 1343, 1921, 2171, 2263, 2369, 2509, 3077, 3097, 3427, 3523, 3683, 4171, 4537, 4541, 4811, 5213, 5263, 5389, 5543, 6107, 6227, 6707, 7123, 7241, 8279, 8593, 8621, 8717, 8857, 8873, 9353, 9607, 10411, 10537, 11359, 11461, 11567, 11747, 11761, 11819

Offset

1,1

Links

John Cerkan, Table of n, a(n) for n = 1..10000

Mathematica

pmp11Q[n_]:=Module[{fi=FactorInteger[n][[All, 1]]}, Mod[fi[[2]], fi[[1]]] == 11]; Select[ Range[12000], PrimeNu[#]==PrimeOmega[#]==2&&pmp11Q[#]&] (* Harvey P. Dale, Jun 25 2018 *)

Prog

(Python)
from sympy import factorint
def is_A064909(n):
    f = factorint(n)
    return (sum([f[i] for i in f]) == 2) and (max(f) % min(f) == 11)
def first_A064909(n):
    x = 1
    an = []
    while len(an) < n:
        if is_A064909(x): an.append(x)
        x += 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]) == 11);

Crossrefs

Cf. A001358 (p2 mod p1 = 0), A064899-A064911.

Sequence in context: A269759 A317174 A020286 * A051980 A020271 A290338

Adjacent sequences: A064906 A064907 A064908 * A064910 A064911 A064912

Keyword

nonn

Author

Patrick De Geest, Oct 13 2001

Extensions

Offset and name fixed by John Cerkan, Apr 12 2018

Status

approved