A378361 Octagonal indices of numbers that are both octagonal and octagonal pyramidal.

0, 1, 19, 45, 6413415, 16068720

Offset

1,3

Links

Table of n, a(n) for n=1..6.

Example

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

Crossrefs

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

Cf. A344376.

Sequence in context: A359558 A245864 A183624 * A115249 A325451 A135029

Adjacent sequences: A378358 A378359 A378360 * A378362 A378363 A378364

Keyword

nonn,fini,full

Author

Kelvin Voskuijl, Nov 23 2024

Status

approved