A100256 Squares of second pentagonal numbers: (1/4) n^2(3n+1)^2.

0, 4, 49, 225, 676, 1600, 3249, 5929, 10000, 15876, 24025, 34969, 49284, 67600, 90601, 119025, 153664, 195364, 245025, 303601, 372100, 451584, 543169, 648025, 767376, 902500, 1054729, 1225449, 1416100, 1628176, 1863225, 2122849

Offset

0,2

Links

Table of n, a(n) for n=0..31.

L. Euler, De mirabilibus proprietatibus numerorum pentagonalium, par. 29

L. Euler, On the remarkable properties of the pentagonal numbers

Formula

G.f.: x*(4+29*x+20*x^2+x^3)/(1-x)^5. [Colin Barker, Feb 14 2012]

Crossrefs

Equals A005449(n)^2. Cf. A100255.

Sequence in context: A166826 A295535 A078187 * A163944 A000596 A113525

Adjacent sequences: A100253 A100254 A100255 * A100257 A100258 A100259

Keyword

nonn

Author

Ralf Stephan, Nov 13 2004

Status

approved