OFFSET
2,1
COMMENTS
a(4) > 10^19 if it exists. - Michael S. Branicky, Feb 23 2023
LINKS
Eric Weisstein's World of Mathematics, Pyramidal Number
EXAMPLE
For n = 2: 12880 = 91 + ... + 903 = 300 + ... + 990.
For n = 3: 18896570 = 708561 + ... + 1021384 = 2604125 + ... + 2796160.
CROSSREFS
KEYWORD
nonn,bref,more
AUTHOR
Ilya Gutkovskiy, Feb 23 2023
STATUS
approved