A130855 2n appears 2n+1 times, 2n+1 appears 2n times.

0, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12

Offset

0,2

Links

Robert Israel, Table of n, a(n) for n = 0..10000

Formula

G.f.: (1-x)^(-1)*Sum_{n>=0} (z^(2*n^2+n+1) + z^(2*n^2+3*n+1)). - Robert Israel, Jun 03 2019

Maple

seq(op([(2*n)$(2*n+1), (2*n+1)$(2*n)]), n=0..14); # Robert Israel, Jun 03 2019

Mathematica

Table[{PadRight[{}, 2n+1, 2n], PadRight[{}, 2n, 2n+1]}, {n, 0, 10}]//Flatten (* Harvey P. Dale, Aug 01 2017 *)

Crossrefs

Sequence in context: A345380 A367128 A028829 * A235963 A100196 A278078

Adjacent sequences: A130852 A130853 A130854 * A130856 A130857 A130858

Keyword

nonn

Author

Paul Curtz, Jul 22 2007

Status

approved