

A136033


a(n) = smallest number k such that number of prime factors of 2^k1 is exactly n (counted with multiplicity).


1



2, 4, 6, 16, 12, 18, 24, 40, 54, 36, 102, 110, 60, 72, 108, 140, 120, 156, 144, 200, 216, 210, 240, 180, 456, 288, 336, 300, 396, 480, 882, 360, 468, 700
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS

Table of n, a(n) for n=1..34.


MAPLE

N:= 24: # to get a(1) to a(N)
unknown:= N:
for k from 2 while unknown > 0 do
q:= numtheory:bigomega(2^k1);
if q <= N and not assigned(A[q]) then
A[q]:= k;
unknown:= unknown  1;
fi
od:
seq(A[i], i=1..N); # Robert Israel, Oct 24 2014


PROG

(PARI) a(n) = {k = 1; while(bigomega(2^k1) != n, k++); k; } \\ Michel Marcus, Nov 04 2013


CROSSREFS

Cf. A000225, A003260, A016047, A046051, A049479, A088863, A136030, A136031.
Sequence in context: A127679 A049022 A209867 * A099315 A005179 A037019
Adjacent sequences: A136030 A136031 A136032 * A136034 A136035 A136036


KEYWORD

nonn,more,hard


AUTHOR

Artur Jasinski, Dec 11 2007


EXTENSIONS

a(15)a(20) from Michel Marcus, Nov 04 2013
a(21)a(24) from Derek Orr, Oct 23 2014
a(25)a(34) from Jinyuan Wang, Jun 07 2019


STATUS

approved



