A278249 - OEIS

%I #9 Nov 22 2016 21:49:42

%S 1,2,4,6,6,6,12,6,36,6,60,6,6,30,60,6,6,30,12,210,210,180,12,30,12,30,

%T 900,60,6,6,60,30,12,210,720,30,420,30,60,6,12,30,60,6,6,60,60,30,60,

%U 210,2520,210,210,30,180,210,60,120,60,210,6,30,60,30,6,30,60,30,6,30,12,30,60,30,420,210,60,30,420,60,6,30,2520,30,30,210,12,210,60,210

%N Least number with the prime signature of A000123(n), the number of partitions of 2n into powers of 2.

%H Antti Karttunen, <a href="/A278249/b278249.txt">Table of n, a(n) for n = 0..321</a>

%F a(n) = A046523(A000123(n)).

%o (PARI)

%o A000123(n) = if(n<1, n==0, A000123(n\2)+A000123(n-1)); \\ From _M. F. Hasler_, Apr 30 2009 (?)

%o A046523(n) = my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]) \\ From _Charles R Greathouse IV_, Aug 17 2011

%o A278249(n) = A046523(A000123(n));

%o for(n=0, 321, write("b278249.txt", n, " ", A278249(n)));

%o (Scheme) (define (A278249 n) (A046523 (A000123 n)))

%Y Cf. A000123, A046523.

%Y Cf. also A278241.

%K nonn

%O 0,2

%A _Antti Karttunen_, Nov 22 2016