0,2

P. De Geest, Palindromic Quasipronics of the form n(n+x)

a(n)= (n+4)^2 -4^2 = n*(n+8), n>=0.

G.f.: x*(9-7*x)/(1-x)^3.

a:=n->sum(n, j=9..n): seq(a(n), n=8..53); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Feb 12 2007

a(n-4), n>=5, fourth column (used for the Brackett series of the hydrogen atom) of triangle A120070.

Adjacent sequences: A028563 A028564 A028565 this_sequence A028567 A028568 A028569

Sequence in context: A094196 A017497 A059108 this_sequence A128153 A109805 A013573

nonn

Patrick De Geest (pdg(AT)worldofnumbers.com)