A368072 -id:A368072 - cp's OEIS frontend

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A368073 Number of representations of n as the difference of two positive square pyramidal numbers.

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

Offset: 1

Ilya Gutkovskiy, Dec 10 2023

nonn

			a(25) = 2: 25 = 30 - 5 = 55 - 30.

Eric Weisstein's World of Mathematics, Square Pyramidal Number

Cf. A000330, A100073, A296338, A368072.

A368076 a(n) is the least integer that can be expressed as the difference of two positive tetrahedral numbers in exactly n ways.

Original entry on oeis.org

3, 36, 2180, 10053736

Offset: 1

Ilya Gutkovskiy, Dec 10 2023

Index of first occurrence of n in A368072.

			a(2) = 36: 36 = 56 - 20 = 120 - 84.

Eric Weisstein's World of Mathematics, Tetrahedral Number

Cf. A000292, A136108, A334007, A368072.

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