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

Author

Ralf Stephan, Nov 13 2004

Keywords

• nonn
• easy

Links

• Leonhard Euler, De mirabilibus proprietatibus numerorum pentagonalium, par. 29
• Leonhard Euler, On the remarkable properties of the pentagonal numbers, arXiv:math/0505373 [math.HO], 2006.

Crossrefs

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

Formula

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