A378918 Indices of octagonal pyramidal numbers that are both octagonal and octagonal pyramidal.

0, 1, 10, 18, 49785, 91839

Offset: 1

Author

Kelvin Voskuijl, Dec 10 2024

Keywords

• nonn
• fini
• full

Examples

			10 is a term because the 10th octagonal pyramidal number (1045) is also the 19th octagonal number.
		

Crossrefs

Cf. A000567 (octagonal numbers), A002414 (octagonal pyramidal numbers).

Cf. A344376.

Cf. A378361 (octagonal indices).

Formula

A344376(n) = A002414(a(n)).