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A045720 3-fold convolution of A001700(n), n >= 0. 4
1, 9, 57, 312, 1578, 7599, 35401, 161052, 719790, 3173090, 13836426, 59803104, 256596276, 1094249019, 4642178601, 19605872724, 82483419846, 345839048094, 1445715336366, 6027524015664, 25070662980876, 104056307673654 (list; graph; refs; listen; history; internal format)
OFFSET

0,2

REFERENCES

D.R. Snow, Spreadsheets, Power Series, Generating Functions and Integers, The College Maths. J. 20 (1989) 149.

FORMULA

a(n) = (n+5)*binomial(2*(n+3), n+3)/4 - 3*2^(2*n+3); G.f.: (c(x)/sqrt(1-4*x))^3, where c(x) = g.f. for Catalan numbers A000108; recursion: a(n)=(2*(2*n+7)/(n+3))*a(n-1)+(3/(n+3))*A008549(n+1), a(0)=1.

CROSSREFS

Cf. A001700, A000108, A008549.

Sequence in context: A064838 A027210 A192054 * A014916 A045635 A026896

Adjacent sequences:  A045717 A045718 A045719 * A045721 A045722 A045723

KEYWORD

easy,nonn

AUTHOR

Wolfdieter Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de)

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Last modified February 17 17:51 EST 2012. Contains 206061 sequences.