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A240944 Number of compositions of n into square parts k^2 where there are k sorts of part k^2. 4
1, 1, 1, 1, 3, 5, 7, 9, 15, 28, 45, 66, 99, 164, 269, 422, 651, 1028, 1654, 2637, 4149, 6522, 10350, 16467, 26091, 41205, 65174, 103339, 163833, 259361, 410376, 649827, 1029543, 1630725, 2581848, 4087797, 6473832, 10253370, 16237375, 25711316, 40714953, 64478427, 102111230, 161701086, 256062990, 405499697, 642156651 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..1000

FORMULA

G.f.: 1/(1 - sum(k>=1, k * x^(k^2)) ).

MAPLE

a:= proc(n) option remember; `if`(n=0, 1, `if`(n<0, 0,

      add(k*a(n-k^2), k=1..isqrt(n))))

    end:

seq(a(n), n=0..50);  # Alois P. Heinz, Aug 04 2014

PROG

(PARI) N=66; x='x+O('x^N); Vec(1/(1 - sum(k=1, 1+sqrtint(N), k * x^(k^2))) )

CROSSREFS

Cf. A006456 (compositions into squares).

Sequence in context: A327823 A102633 A052942 * A117913 A064411 A146556

Adjacent sequences:  A240941 A240942 A240943 * A240945 A240946 A240947

KEYWORD

nonn

AUTHOR

Joerg Arndt, Aug 04 2014

STATUS

approved

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Last modified May 14 09:34 EDT 2021. Contains 343879 sequences. (Running on oeis4.)