A112458 Let b(n) = A112455(n). Then b(n)/n is an integer iff n is prime (at least for the first few values, as for the Perrin sequence). This sequence is the values of b(p)/p, where p is the n th prime.

1, 1, -1, 1, 0, 1, 3, -3, 2, -16, 13, 58, 93, -48, 257, -508, -2439, 3751, 3120, 21824, -28485, -49886, -184653, -158325, -1238859, 2621639, -6281879, -10666638, 5587636, -32300736, -541428896, -309499443, -3404250996, 4487895627, 30910925690, -33820854920, -104685213761, 219810779538

Offset: 1

Author

Anthony C Robin, Dec 13 2005

Keywords

• sign

References

• See Perrin sequences

Programs

Maple

A112455 := proc(n) option remember; if n <= 3 then op(n+1,[ -3,0,2,3]) ; else -A112455(n-2)-A112455(n-3) ; fi ; end: A112458 := proc(n) local p ; p := ithprime(n) ; A112455(p)/p ; end: seq(A112458(n),n=1..80) ; # R. J. Mathar, Aug 24 2007

Extensions

More terms from R. J. Mathar, Aug 24 2007