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A325301
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a(n) is the number of edges of the stepped pyramid with n levels described in A245092.
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2
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12, 21, 36, 51, 63, 84, 96, 117, 138, 165, 177, 204, 216, 240, 273, 306, 318, 351, 363
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listen;
history;
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OFFSET
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1,1
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COMMENTS
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To calculate a(n) consider that levels greater than n do not exist.
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LINKS
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Table of n, a(n) for n=1..19.
Omar E. Pol, Perspective view of the pyramid (first 16 levels)
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FORMULA
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a(n) = A325300(n) + A325302(n) - 2 (Euler's formula).
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EXAMPLE
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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.
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CROSSREFS
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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 * A219542 A137480 A316267
Adjacent sequences: A325298 A325299 A325300 * A325302 A325303 A325304
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KEYWORD
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nonn,more
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AUTHOR
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Omar E. Pol, Apr 16 2019
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STATUS
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approved
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