A378361 - OEIS

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A378361

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

0

0, 1, 19, 45, 6413415, 16068720

(list; graph; refs; listen; history; text; internal format)

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).

Sequence in context: A359558 A245864 A183624 * A115249 A325451 A135029

Adjacent sequences: A378358 A378359 A378360 * A378363 A378365 A378366

KEYWORD

nonn,fini,full,new

AUTHOR

Kelvin Voskuijl, Nov 23 2024

STATUS

approved