The On-Line Encyclopedia of Integer Sequences (OEIS)

A152548 revision #19

A152548

Sum of squared terms in rows of triangle A152547: a(n) = Sum_{k=0..C(n,[n/2])-1} A152547(n,k)^2.

1, 4, 10, 24, 54, 120, 260, 560, 1190, 2520, 5292, 11088, 23100, 48048, 99528, 205920, 424710, 875160, 1798940, 3695120, 7574996, 15519504, 31744440, 64899744, 132503644, 270415600, 551231800, 1123264800, 2286646200, 4653525600

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Table of n, a(n) for n=0..29.

FORMULA

G.f.: A(x) = sqrt( (1+2x)/(1-2x)^3 ).

a(n) = Sum_{k=0..[(n+1)/2]} C(n+1, k)*(n+1-2k)^3/(n+1).

a(n) = A107233(n)/(n+1).

Self-convolution equals A014477.

E.g.f.: ((1 + 4*x)*BesselI(0, 2*x) + 4*x*BesselI(1, 2*x)). - Peter Luschny, Aug 26 2012

a(n) = (-2)^n*hypergeom([-n,3/2], [1], 2). - Peter Luschny, Apr 26 2016

Recurrence: (n+1)*a(n+1) = 4*a(n) + 4*n*a(n-1). - Vladimir Reshetnikov, Oct 10 2016

a(n) ~ 2^(n + 3/2) * sqrt(n/Pi). - Vaclav Kotesovec, Oct 11 2016

MAPLE

seq(simplify((-2)^n*hypergeom([-n, 3/2], [1], 2)), n=0..29); # Peter Luschny, Apr 26 2016

MATHEMATICA

CoefficientList[Series[Sqrt[(1+2x)/(1-2x)^3], {x, 0, 30}], x] (* Harvey P. Dale, Jan 04 2016 *)

PROG

(PARI) a(n)=sum(k=0, floor((n+1)/2), binomial(n+1, k)*(n+1-2*k)^3)/(n+1)

CROSSREFS

Cf. A152547, A107233, A014477.

Sequence in context: A279851 A266367 A316528 * A273228 A291727 A291224

Adjacent sequences: A152545 A152546 A152547 * A152549 A152550 A152551

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Dec 14 2008

STATUS

reviewed