A239928 - OEIS

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A239928

Expansion of F(x^2, x) where F(x,y) is the g.f. of A239927.

1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 2, 0, 1, 3, 1, 1, 4, 3, 2, 5, 6, 4, 6, 10, 8, 9, 15, 15, 15, 22, 26, 26, 33, 43, 45, 52, 69, 76, 85, 109, 127, 141, 173, 209, 235, 278, 340, 390, 452, 550, 643, 742, 890, 1054, 1221, 1445, 1720, 2007, 2356, 2803, 3291, 3853, 4568, 5385, 6309, 7450, 8800, 10330, 12164, 14372, 16905, 19879

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,14

COMMENTS

What does this sequence count?

LINKS

Joerg Arndt, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: 1/(1 - x^3/(1 - x^7/(1 - x^11/(1 - x^15/(1 - x^19/(1 - x^23/( ... ))))))).

PROG

(PARI) N=66; x='x+O('x^N);

F(x, y, d=0)=if (d>N, 1, 1 / (1-x*y * F(x, x^2*y, d+1) ) );

Vec( F(x^2, x) )

CROSSREFS

Cf. A000108 (F(1, x)), A143951 (F(x, 1)), A005169 (F(x, x), with interlaced zeros), A227310 (F(x, x^2)).

Sequence in context: A362463 A263401 A369814 * A114912 A231723 A342720

Adjacent sequences: A239925 A239926 A239927 * A239929 A239930 A239931

KEYWORD

nonn

AUTHOR

Joerg Arndt, Mar 29 2014

STATUS

approved