A334034 a(n) is the least integer that can be expressed as the difference of two pentagonal numbers in exactly n ways.

1, 22, 70, 715, 1330, 4025, 6370, 14014, 17290, 25025, 45815, 73150, 121030, 95095, 85085, 256025, 350350, 432250, 1179178, 425425, 575575, 734825, 950950, 1926925, 3751930, 2187185, 1616615, 1956955, 3148145, 3658655, 4029025, 2977975, 4352425, 6656650, 13918450

Offset: 1

Author

Ilya Gutkovskiy, Apr 12 2020

Keywords

• nonn

Comments

The least integer that can be expressed as the sum of one or more consecutive numbers congruent to 1 mod 3 in exactly n ways.

Index of first occurrence of n in A333815.

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..72
• Eric Weisstein's World of Mathematics, Pentagonal Number
• Index to sequences related to polygonal numbers

Crossrefs

Cf. A000326, A016777, A038547, A068314, A333815, A334008, A334035, A334036, A334037.

Extensions

More terms from Jinyuan Wang, Apr 13 2020