A269795 Number of similarity classes of vectors with minimal Ducci period n.

2, 0, 6, 2, 30, 24, 126, 28, 504, 480, 2046, 990, 8190, 8064, 32730, 4064, 131070, 130536, 524286, 261630, 2097018, 2095104, 8388606, 2096100, 33554400, 33546240, 134217216, 67100670, 536870910, 536837640, 2147483646, 134213632, 8589932538, 8589803520, 34359738210

Offset

1,1

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]) &]; Array[a, 35] (* Amiram Eldar, Aug 24 2023 *)

Prog

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

Crossrefs

Sequence in context: A294779 A049257 A054877 * A372016 A095834 A106828

Adjacent sequences: A269792 A269793 A269794 * A269796 A269797 A269798

Keyword

nonn

Author

Michel Marcus, Mar 05 2016

Status

approved