A055497 a(-1) = 4, a(0) = 5; thereafter a(n) = 4 + (Product_{k=1..n} prime(k))^2.

4, 5, 8, 40, 904, 44104, 5336104, 901800904, 260620460104, 94083986096104, 49770428644836904, 41856930490307832904, 40224510201185827416904, 55067354465423397733736104, 92568222856376731590410384104

Offset

-1,1

References

M. Aigner and G. M. Ziegler, Proofs from The Book, Springer-Verlag, Berlin, 1999; see p. 21.

Links

Harvey P. Dale, Table of n, a(n) for n = -1..195

Example

a(1) = 4 + 2^2 = 8, a(2) = 4 + (2*3)^2 = 40.

Mathematica

Join[{4, 5}, Table[4+Product[Prime[k], {k, n}]^2, {n, 15}]] (* Harvey P. Dale, Dec 04 2017 *)

Crossrefs

Sequence in context: A240790 A229861 A140315 * A194419 A175380 A263151

Adjacent sequences: A055494 A055495 A055496 * A055498 A055499 A055500

Keyword

nonn

Author

N. J. A. Sloane, Jul 07 2000 Definition and offset changed by N. J. A. Sloane, Dec 04 2017

Status

approved