A282738 First differences of A282737.

1, 2, 1, 4, 1, 5, 1, 6, 1, 7, 1, 8, 1, 9, 1, 10, 1, 11, 1, 12, 1, 13, 1, 14, 1, 15, 1, 16, 1, 17, 1, 18, 1, 19, 1, 20, 1, 21, 1, 22, 1, 23, 1, 24, 1, 25, 1, 26, 1, 27, 1, 28, 1, 29, 1, 30, 1, 31, 1, 32, 1, 33, 1, 34, 1, 35, 1, 36, 1, 37, 1, 38, 1, 39, 1, 40, 1, 41, 1

Offset

0,2

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (0,2,0,-1).

Formula

G.f.: (1 + 2*x - x^2 - x^5) / (1 - x^2)^2.

From Colin Barker, Mar 04 2017: (Start)

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

a(n) = 1 for n>1 and even.

a(n) = (n+5) / 2 for n>1 and odd.

(End)

Prog

(PARI) Vec((1 + 2*x - x^2 - x^5) / ((1 - x)^2*(1 + x)^2) + O(x^100)) \\ Colin Barker, Mar 04 2017

Crossrefs

Cf. A282737.

A152271 and A133622 are very similar sequences.

Sequence in context: A284652 A261242 A088296 * A093890 A325609 A006306

Adjacent sequences: A282735 A282736 A282737 * A282739 A282740 A282741

Keyword

nonn,easy

Author

N. J. A. Sloane, Mar 04 2017

Status

approved