OFFSET
1,2
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..11
Wikipedia, Polygonal number
EXAMPLE
1, 19, 19224, 19224631909 are 19-gonal.
PROG
(PARI) enneadecagonal(n)=ispolygonal(n, 19)
first(m)=my(s=""); s="1"; print1(1, ", "); for(i=2, m, n=1; while(!enneadecagonal(eval(concat(s, Str(n)))), n++); print1(n, ", "); s=concat(s, Str(n)))
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Anders Hellström, Nov 26 2015
EXTENSIONS
a(5)-a(8) from Chai Wah Wu, Mar 16 2018
STATUS
approved