A350423 a(n) is the smallest n-gonal number which can be represented as the sum of n distinct nonzero n-gonal numbers in exactly n ways, or -1 if none exists.

190, 289, 330, 561

Offset

3,1

Links

Table of n, a(n) for n=3..6.

Eric Weisstein's World of Mathematics, Polygonal Number

Example

For n = 3: 190 = 1 + 36 + 153 = 15 + 55 + 120 = 21 + 78 + 91.

Crossrefs

Cf. A057145, A350405.

Sequence in context: A260762 A218292 A333834 * A051979 A097647 A248995

Adjacent sequences: A350420 A350421 A350422 * A350424 A350425 A350426

Keyword

nonn,more

Author

Ilya Gutkovskiy, Dec 31 2021

Status

approved