A175410 a(n) = (b(m)-1)*b(m) = Sum_{n=b(m)+1,...,c(m)}n, b=A046174, c=A046175, m=n+1.

132, 27060, 5269320, 1022496552, 198362899020, 38481433358940, 7465200453136272, 1448210416843244880, 280945355811546307860, 54501950819034511436292, 10573097513564898455783640

Offset

1,1

Comments

Solution to (b-1)*b = (c^2+2bc+c)/2.

Links

Table of n, a(n) for n=1..11.

Example

A046174(2) = 12, then 11*12 = 13+14+15+16+17+18+19+20 = 132, is a term. A046174(3) = 165, then 164*165 = 166+167+,....,+285 = 27060, is a term.

Mathematica

lst={}; k=1; j=0; Do[b=14*k-j-2; AppendTo[lst, (b-1)*b]; j=k; k=b, {n, 1, 16}]; lst

Crossrefs

A046174, A046175.

Sequence in context: A269042 A216787 A239817 * A146522 A183500 A146545

Adjacent sequences: A175407 A175408 A175409 * A175411 A175412 A175413

Keyword

nonn

Author

Manuel Valdivia, May 05 2010

Status

approved