A182589 Number of p-gons in cubic curve, where p = n-th prime.

8, 24, 216, 2376, 381672, 5163480, 1010595960, 14467313448, 3059511345864, 9938978525015640, 148764065249108232, 510526106263606993560, 117943982401534505983800, 1799331452450089752726504, 421426396352475869646014856, 1530747894615220749248821030680

Offset

1,1

Links

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

M. Picquet, Applications de la représentation des courbes du troisième degré, Journal de l'École Polytechnique, Paris, 35 (1884), 31-100.

Formula

a(n) = 8*(2^(p-2)+1)*(2^(p-1)-1)/p where p = n-th prime.

Prog

(PARI) a(n) = my(p=prime(n)); 8*(2^(p-2)+1)*(2^(p-1)-1)/p; \\ Michel Marcus, Dec 10 2014
(Magma) [8*(2^(p-2)+1)*(2^(p-1)-1)/p: p in PrimesUpTo(60)]; // Vincenzo Librandi, Dec 11 2014

Crossrefs

A subsequence of A005782. Cf. A200905.

Sequence in context: A221784 A052656 A094061 * A002268 A050893 A037025

Adjacent sequences: A182586 A182587 A182588 * A182590 A182591 A182592

Keyword

nonn

Author

N. J. A. Sloane, Nov 23 2011

Status

approved