OFFSET
1,4
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..451
MAPLE
a[1] := 1:for n from 2 to 100 do a[n] := floor(evalf(-1/2+1/2*sqrt(1+8*(n-1)*a[n-1])+1/10^50, 300)):a[n] := a[n]*(a[n]+1)/2:od:seq(a[l], l=1..100);
MATHEMATICA
nxt[{n_, a_}]:=Module[{c=Floor[(Sqrt[1+8n*a]-1)/2]}, {n+1, (c(c+1))/2}]; NestList[nxt, {1, 1}, 20][[All, 2]] (* Harvey P. Dale, Jun 04 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amarnath Murthy, Oct 26 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 26 2003
STATUS
approved