OFFSET
0,4
LINKS
Colin Barker, Table of n, a(n) for n = 0..169
Wikipedia, Centered polygonal number
EXAMPLE
a(4) = cpg(3, 4) * cpg(4, 4) = 19 * 25 = 475.
PROG
(PARI) cpg(m, n) = m*n*(n-1)/2+1
vector(50, n, n--; prod(m=3, n, cpg(m, n)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Colin Barker, Apr 16 2015
STATUS
approved