A325301 a(n) is the number of edges of the stepped pyramid with n levels described in A245092.

12, 21, 36, 51, 63, 84, 96, 117, 138, 165, 177, 204, 216, 240, 273, 306, 318, 351, 363

Offset

1,1

Comments

To calculate a(n) consider that levels greater than n do not exist.

Links

Table of n, a(n) for n=1..19.

Omar E. Pol, Perspective view of the pyramid (first 16 levels)

Formula

a(n) = A325300(n) + A325302(n) - 2 (Euler's formula).

Example

For n = 1 the first level of the stepped pyramid (starting from the top) is a cube, and a cube has 12 edges, so a(1) = 12.

Crossrefs

Cf. A325300 (number of faces), A325302 (number of vertices).

Cf. A196020, A235791, A236104, A237270, A237271, A237591, A237593, A245092, A262626, A294848, A294849, A317109, A323648.

Sequence in context: A071263 A241503 A226186 * A351478 A219542 A354984

Adjacent sequences: A325298 A325299 A325300 * A325302 A325303 A325304

Keyword

nonn,more

Author

Omar E. Pol, Apr 16 2019

Status

approved