A237581 A024282(n)/2^(n-1)

0, 1, -4, 31, -396, 7577, -206552, 7672397, -374053288, 23212430217, -1787864588588, 167392122209915, -18724565706803572, 2466364070480613097, -377841494631185170944, 66613038231424017296385, -13390635287181333029590160

Offset

0,3

Comments

Parity of indices is the same as parity of values, i.e., a(n) = n (mod 2). Even terms are of the form a(2n) = -4*b(n), b=(0, 1, 99, 51638, 93513322, 446966147147, ...).

Motivated by the fact that A024282(n) is divisible by 2^(n-1). One might also consider A024282(n)/4^floor(n/2)*(-1)^(n+1) = (0, 1, 2, 31, 198, 7577, 103276, 7672397, 187026644, ...)

Links

Table of n, a(n) for n=0..16.

Prog

(PARI) A237581 = n->A024282(n)>>(n-1)

Crossrefs

Sequence in context: A323568 A174324 A211194 * A319074 A195195 A141827

Adjacent sequences: A237578 A237579 A237580 * A237582 A237583 A237584

Keyword

sign

Author

M. F. Hasler, Feb 09 2014

Status

approved