A255218 Numbers k such that 12*k+1, 24*k+1, 36*k+1 and 72*k+1 are all prime.
28, 103, 190, 253, 355, 848, 1328, 1783, 1898, 1958, 1988, 2170, 2213, 3003, 3533, 3808, 3913, 3988, 4450, 4488, 4593, 4800, 5460, 5808, 5853, 6448, 6545, 6903, 7103, 7238, 7295, 7400, 7483, 7693, 8533, 9310, 9780, 10260, 10885, 12185, 12628, 15513, 16163
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Harvey P. Dale)
- Umberto Cerruti, Pseudoprimi di Fermat e numeri di Carmichael (in Italian), p. 14.
Programs
-
Magma
[n: n in [0..20000] | IsPrime(12*n+1) and IsPrime(24*n+1) and IsPrime(36*n+1) and IsPrime(72*n+1)];
-
Magma
[n: n in [0..20000] | forall{i: i in Divisors(6) | IsPrime(12*i*n+1)}]; -
Mathematica
Select[Range[10000], PrimeQ[12 # + 1] && PrimeQ[24 # + 1] && PrimeQ[36 # + 1] && PrimeQ[72 # + 1] &] Select[Range[17000],AllTrue[{12,24,36,72}#+1,PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 16 2016 *)