

A138187


Hankel transform of C(2n+3,n).


1



1, 4, 3, 3, 8, 5, 5, 12, 7, 7, 16, 9, 9, 20, 11, 11, 24, 13, 13, 28, 15, 15, 32, 17, 17, 36, 19, 19, 40, 21, 21, 44, 23, 23, 48, 25, 25, 52, 27, 27, 56, 29, 29, 60, 31, 31, 64, 33, 33, 68, 35, 35, 72, 37, 37, 76, 39, 39, 80, 41
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OFFSET

0,2


COMMENTS

Hankel transform of A002054(n+1). Hankel transform of A002054(n) is A057078(n+1).
Partial sums are A138188.
The sequence 1,1,4,3,3,... has general term sum{k=0..n, C(n+k,2k)*(1)^(nk)*(n+k+1)}. [From Paul Barry, Apr 19 2010]


LINKS

Table of n, a(n) for n=0..59.
Index entries for linear recurrences with constant coefficients, signature (2,3,2,1).


FORMULA

G.f. : (12x2x^2x^3)/(1+x+x^2)^2;


CROSSREFS

Sequence in context: A006994 A038627 A155835 * A105342 A323601 A055525
Adjacent sequences: A138184 A138185 A138186 * A138188 A138189 A138190


KEYWORD

easy,sign


AUTHOR

Paul Barry, Mar 04 2008


STATUS

approved



