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A239928 Expansion of F(x^2, x) where F(x,y) is the g.f. of A239927. 2
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: A130504 A044942 A263401 * A114912 A231723 A342720

Adjacent sequences:  A239925 A239926 A239927 * A239929 A239930 A239931

KEYWORD

nonn

AUTHOR

Joerg Arndt, Mar 29 2014

STATUS

approved

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Last modified September 16 18:26 EDT 2021. Contains 347473 sequences. (Running on oeis4.)