OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Polygonal Number.
PROG
(PARI) is(n, c=2)=for(s=3, 16, ispolygonal(n, s)&&!c--&&return(s)) \\ M. F. Hasler, Jan 19 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Nov 30 2003
STATUS
approved