A350397 a(n) is the smallest number which can be represented as the sum of n distinct nonzero n-gonal pyramidal numbers in exactly n ways, or -1 if no such number exists.

305, 1980, 1900, 3321, 5256, 8310, 12516, 17108, 24832, 34249, 42381, 61697, 78766, 106956, 132994, 170325, 203415, 266595, 322943, 393828, 475520, 569416, 695799, 823447, 958300, 1149125, 1313545, 1565055, 1802736, 2088119, 2376250, 2748270, 3135195, 3548876

Offset

3,1

Links

Martin Ehrenstein, Table of n, a(n) for n = 3..52

Eric Weisstein's World of Mathematics, Pyramidal Number

Example

For n = 3: 305 = 1 + 84 + 220 = 20 + 120 + 165 = 56 + 84 + 165.

Crossrefs

Cf. A080851, A350210, A350405.

Sequence in context: A160577 A256603 A058828 * A247344 A220601 A156168

Adjacent sequences: A350394 A350395 A350396 * A350398 A350399 A350400

Keyword

nonn

Author

Ilya Gutkovskiy, Dec 29 2021

Extensions

a(10)-a(22) from Michael S. Branicky, Dec 29 2021

a(23)-a(36) from Martin Ehrenstein, Jan 14 2022

Status

approved