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A088016 To obtain a(n), add the square of the n-th partial sum to the n-th partial sum of the squares, then divide this result by a(n-1), for all n>1, with a(0)=1, a(1)=1. 0
1, 1, 6, 17, 56, 179, 576, 1851, 5950, 19125, 61474, 197597, 635140, 2041543, 6562172, 21092919, 67799386, 217928905, 700493182, 2251609065, 7237391472, 23263290299, 74775653304, 240352858739, 772570939222, 2483290023101 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

FORMULA

a(n)=3a(n-1)+a(n-2)-a(n-3) for n>3; G.f.: (1-2*x+2*x^2-x^3)/(1-3*x-x^2+x^3); A(x)=A030186(x)/(1-x+x^2).

PROG

(PARI) a(n)=(sum(k=0, n-1, a(k))^2+sum(k=0, n-1, a(k)^2))/a(n-1)

CROSSREFS

Cf. A030186, A087640.

Sequence in context: A128525 A083334 A199113 * A010330 A109311 A151350

Adjacent sequences:  A088013 A088014 A088015 * A088017 A088018 A088019

KEYWORD

nonn

AUTHOR

Paul D. Hanna (pauldhanna(AT)juno.com), Sep 18 2003

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Last modified February 14 11:36 EST 2012. Contains 205623 sequences.