A145647 First differences of A145646.

2734, 4556, 6379, 8202, 10024, 11846, 13669, 15492, 17314, 19136, 20959, 22782, 24604

Offset

1,1

Comments

Essentially (rounding effects ignored) 2*n+1 divided by the scaled constant A081821.

Links

Table of n, a(n) for n=1..13.

Formula

Conjectures from Colin Barker, May 08 2019: (Start)

G.f.: x*(2734 - 912*x + 2735*x^2 - 912*x^3) / ((1 - x)^2*(1 + x^2)).

a(n) = (3646 + (-i)^n + i^n + 7290*n) / 4 where i = sqrt(-1).

a(n) = 2*a(n-1) - 2*a(n-2) + 2*a(n-3) - a(n-4) for n>4.

(End)

Crossrefs

Cf. A081821, A145646.

Sequence in context: A076575 A015423 A260543 * A251946 A045155 A251989

Adjacent sequences: A145644 A145645 A145646 * A145648 A145649 A145650

Keyword

nonn,easy,less

Author

Paul Curtz, Oct 15 2008

Extensions

Edited by N. J. A. Sloane, Oct 15 2008 and R. J. Mathar, Oct 17 2008

Deleted keyword more: we do not want more terms of this ill-defined sequence. - R. J. Mathar, May 12 2019

Status

approved