

A130855


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


1



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
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OFFSET

0,2


LINKS

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


FORMULA

G.f.: (1x)^(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: A334051 A345380 A028829 * A235963 A100196 A278078
Adjacent sequences: A130852 A130853 A130854 * A130856 A130857 A130858


KEYWORD

nonn


AUTHOR

Paul Curtz, Jul 22 2007


STATUS

approved



