The On-Line Encyclopedia of Integer Sequences (OEIS)

A136506 revision #5

A136506

a(n) = C(2^n+2,n).

1, 4, 15, 120, 3060, 278256, 90858768, 105637584000, 436355999662176, 6431591598617108352, 340881559632021623909760, 65533747894341651530074060800, 46081376018330435634530315478453248

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OFFSET

0,2

LINKS

Table of n, a(n) for n=0..12.

FORMULA

G.f.: A(x) = Sum_{n>=0} (1 + 2^n*x)^2 * log(1 + 2^n*x)^n/n!.

MATHEMATICA

Table[Binomial[2^n+2, n], {n, 0, 20}] (* Harvey P. Dale, June 20 2011 *)

PROG

(PARI) {a(n)=polcoeff(sum(i=0, n, (1+2^i*x +x*O(x^n))^2*log(1+2^i*x +x*O(x^n))^i/i!), n)}

CROSSREFS

Cf. A014070 (C(2^n, n)), A136505 (C(2^n+1, n)); A136507.

Sequence in context: A354889 A197703 A352608 * A375994 A362499 A323564

Adjacent sequences: A136503 A136504 A136505 * A136507 A136508 A136509

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jan 01 2008

STATUS

approved