A255578 Carmichael numbers of the form (12*k+1)*(24*k+1)*(36*k+1)*(72*k+1), where 12*k+1, 24*k+1, 36*k+1 and 72*k+1 are all primes.

461574735553, 84154807001953, 973694665856161, 3060522900274753, 11861640972220321, 386096840467598593, 2322064552169233153, 7545246852649391713, 9688364125836900193, 10972742858243841313, 11660828668219467073, 16553878978808515681, 17905475062325518273

Offset: 1

Author

Vincenzo Librandi, Feb 26 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. 14.

Crossrefs

Cf. A002997, A255218.

Programs

Magma

[(12*n+1)*(24*n+1)*(36*n+1)*(72*n+1): n in [1..4000] | IsPrime(12*n+1) and IsPrime(24*n+1) and IsPrime(36*n+1) and IsPrime(72*n+1)];