A255512 Numbers k such that 60*k+41, 90*k+61 and 150*k+101 are all prime.

0, 1, 4, 7, 21, 24, 31, 43, 46, 70, 99, 108, 109, 112, 154, 158, 176, 213, 218, 234, 238, 267, 273, 311, 319, 337, 381, 515, 518, 519, 528, 540, 658, 680, 689, 704, 736, 739, 752, 781, 837, 889, 1012, 1071, 1165, 1170, 1180, 1197, 1233, 1331, 1344, 1373, 1379

Offset: 1

Author

Vincenzo Librandi, Feb 24 2015

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• Umberto Cerruti, Pseudoprimi di Fermat e numeri di Carmichael (in Italian), p. 10.
• Index entries for sequences related to Carmichael numbers.

Crossrefs

Cf. A202113.

Cf. A255441 (Carmichael numbers of the form (60k+41)*(90k+61)*(150k+101)).

Programs

Magma

[n: n in [0..2000]| IsPrime(60*n+41) and IsPrime(90*n+61) and IsPrime(150*n+101)];

Mathematica

Select[Range[0, 1400], PrimeQ[60 # + 41] && PrimeQ[90 # + 61] && PrimeQ[150 # + 101] &]
Select[Range[0,1500],AllTrue[{60#+41,90#+61,150#+101},PrimeQ]&] (* Harvey P. Dale, Jan 13 2024 *)

PARI

is(k) = isprime(60*k + 41) && isprime(90*k + 61) && isprime(150*k + 101); \\ Amiram Eldar, Apr 24 2024