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A359092
a(n) is the index of the smallest n-gonal pyramidal number with binary weight n.
1
5, 4, 9, 5, 20, 9, 29, 18, 40, 61, 52, 77, 121, 85, 235, 165, 281, 393, 438, 586, 645, 884, 1997, 777, 1597, 3598, 4901, 4442, 8249, 4582, 10685, 5362, 28473, 23140, 41305, 41266, 67947, 82953, 101229, 151121, 236221, 257326, 385090, 254725, 713021, 669890
OFFSET
3,1
MATHEMATICA
p[n_, k_] := k*(k + 1)*((n - 2)*k + 5 - n)/6; a[n_] := Module[{k = 1}, While[DigitCount[p[n, k], 2, 1] != n, k++]; k]; Array[a, 40, 3] (* Amiram Eldar, Dec 17 2022 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Ilya Gutkovskiy, Dec 16 2022
STATUS
approved