2,5

Table of n, a(n) for n=2..83.

a(19) = 4 because 2^20 = 1048576 = 232023301 (to scale 5) and (2+3+2+0+2+3+3+0+1)/4 = 4

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]

Cf. A000866.

Sequence in context: A054989 A051631 A073725 * A174807 A181572 A287731

Adjacent sequences: A055220 A055221 A055222 * A055224 A055225 A055226

nonn,base

Lekraj Beedassy, Jun 20 2000

More terms from James A. Sellers, Jul 04 2000

approved