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A091957 a(1)=0, a(2)=1, a(n)=A000217(a(n-1)) + A000217(a(n-2)). 0
0, 1, 1, 2, 4, 13, 101, 5242, 13747054, 94490767454888, 4464252567107002358694986701, 9964775491460730298984873909049635615687553262572198767 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..12.

PROG

(PARI) t(n)=n*(n+1)/2 v=vector(12) v[2]=1 for (i=3, 12, v[i]=t(v[i-1])+t(v[i-2])) v

CROSSREFS

Sequence in context: A216670 A103845 A055463 * A056678 A218655 A193232

Adjacent sequences:  A091954 A091955 A091956 * A091958 A091959 A091960

KEYWORD

nonn

AUTHOR

Jon Perry, Mar 13 2004

STATUS

approved

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Last modified November 14 18:55 EST 2018. Contains 317214 sequences. (Running on oeis4.)