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A055223
One-fourth the digital sum of base 5 representations of 2^n.
3
1, 1, 1, 1, 2, 1, 1, 2, 3, 3, 3, 3, 2, 3, 4, 5, 5, 5, 4, 3, 5, 6, 7, 5, 8, 8, 6, 8, 10, 10, 8, 6, 7, 8, 8, 10, 7, 9, 9, 10, 11, 10, 9, 10, 9, 11, 11, 11, 11, 12, 13, 13, 12, 14, 10, 14, 17, 15, 13, 13, 12, 15, 14, 16, 15, 12, 14, 15, 15, 16, 15, 15, 15, 16, 13, 12, 16, 17, 14, 20, 20, 20
OFFSET
2,5
EXAMPLE
a(19) = 4 because 2^20 = 1048576 = 232023301 (to scale 5) and (2+3+2+0+2+3+3+0+1)/4 = 4
MATHEMATICA
a[n_] := 1/4* Module[{aux = IntegerDigits[2^(n + 1), 5]}, Sum[aux[[i]], {i, 1, Length[aux]}]] [From José María Grau Ribas, Feb 13 2010]
CROSSREFS
Cf. A000866.
Sequence in context: A054989 A051631 A073725 * A174807 A376939 A181572
KEYWORD
nonn,base
AUTHOR
Lekraj Beedassy, Jun 20 2000
EXTENSIONS
More terms from James A. Sellers, Jul 04 2000
STATUS
approved