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A271410 LCM of exponents in binary expansion of 2n. 8
1, 1, 2, 2, 3, 3, 6, 6, 4, 4, 4, 4, 12, 12, 12, 12, 5, 5, 10, 10, 15, 15, 30, 30, 20, 20, 20, 20, 60, 60, 60, 60, 6, 6, 6, 6, 6, 6, 6, 6, 12, 12, 12, 12, 12, 12, 12, 12, 30, 30, 30, 30, 30, 30, 30, 30, 60, 60, 60, 60, 60, 60, 60, 60, 7, 7, 14, 14, 21, 21, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Peter Kagey, Table of n, a(n) for n = 0..10000

EXAMPLE

a(2) = lcm(2) = 2 because 2*2 = 2^2;

a(3) = lcm(1, 2) = 2 because 2*3 = 2^1 + 2^2;

a(7) = lcm(1, 2, 3) = 6 because 2*7 = 2^3 + 2^2 + 2^1.

MATHEMATICA

lcm[n_]:=Module[{idn2=IntegerDigits[n, 2]}, LCM@@Pick[Reverse[Range[ Length[ idn2]]], idn2, 1]]; Join[{1}, Array[lcm, 100]] (* Harvey P. Dale, Jan 24 2019 *)

PROG

(PARI) a(n) = my(ve = select(x->x==1, Vecrev(binary(2*n)), 1)); lcm(vector(#ve, k, ve[k]-1)); \\ Michel Marcus, Apr 12 2016

(PARI) a(n)=lcm(Vec(select(x->x, Vecrev(binary(n)), 1))) \\ Charles R Greathouse IV, Apr 12 2016

CROSSREFS

Cf. A029931, A064894, A073642, A096111, A116417.

Sequence in context: A239962 A175175 A116417 * A196055 A145787 A096111

Adjacent sequences:  A271407 A271408 A271409 * A271411 A271412 A271413

KEYWORD

nonn

AUTHOR

Peter Kagey, Apr 11 2016

STATUS

approved

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Last modified October 16 06:14 EDT 2021. Contains 348040 sequences. (Running on oeis4.)