A365162 a(n) = A269795(n)/2.

1, 0, 3, 1, 15, 12, 63, 14, 252, 240, 1023, 495, 4095, 4032, 16365, 2032, 65535, 65268, 262143, 130815, 1048509, 1047552, 4194303, 1048050, 16777200, 16773120, 67108608, 33550335, 268435455, 268418820, 1073741823, 67106816, 4294966269, 4294901760, 17179869105

Offset

1,3

Links

Table of n, a(n) for n=1..35.

Ron Brown and Jonathan L. Merzel, The number of Ducci sequences with given period, Fibonacci Quart. 45 (2007), no. 2, 115-121.

Mathematica

a[n_] := DivisorSum[n, MoebiusMu[n/#] * 2^(#-IntegerExponent[#, 2]) &] / 2; Array[a, 35]

Prog

(PARI) a(n) = sumdiv(n, d, moebius(n/d)*2^(d-valuation(d, 2))) / 2;

Crossrefs

Cf. A269795.

Sequence in context: A193966 A366120 A113378 * A178657 A257490 A156289

Adjacent sequences: A365159 A365160 A365161 * A365163 A365164 A365165

Keyword

nonn

Author

Amiram Eldar, Aug 24 2023

Status

approved