OFFSET
3,1
COMMENTS
The corresponding indices of n-gonal numbers are in A368074.
LINKS
Eric Weisstein's World of Mathematics, Polygonal Number
EXAMPLE
a(3) = 15: 15 = 21 - 6 = 36 - 21 = 120 - 105.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Ilya Gutkovskiy, Dec 10 2023
STATUS
approved