A227007 Numbers n such that n-1 is squarefree and every prime divisor of n-1 is in the sequence.

2, 3, 4, 7, 8, 15, 22, 43, 44, 87, 130, 259, 302, 603, 904, 1807

Offset

1,1

Comments

The complement of A227006.

1807 is the last term in this sequence. - Charles R Greathouse IV, Jun 27 2013

Links

Table of n, a(n) for n=1..16.

J. M. Grau, A. M. Oller-Marcén and J, Sondow, On the congruence 1^n+2^n+...+n^n == d (mod n), where d divides n, arXiv preprint arXiv:1309.7941, 2013

Mathematica

Needs["NumberTheory`NumberTheoryFunctions`"]; Is[2] = True; Is[{}] = True; Is[n_] := Is[n] = If[ListQ[n], Is[n[[1, 1]]] && Is[Rest[n]], SquareFreeQ[n - 1] && Is[fa[n - 1]]]; Select[1 + Range@10000, Is]

Crossrefs

Cf. A227006.

Sequence in context: A300486 A120611 A092063 * A370858 A126850 A007497

Adjacent sequences: A227004 A227005 A227006 * A227008 A227009 A227010

Keyword

nonn,fini,full

Author

José María Grau Ribas, Jun 27 2013

Status

approved