|
%I #8 Dec 19 2016 02:07:13
%S 1,1,1,2,2,6,2,2,6,12,12,6,2,2,60,30,2,6,120,6,6,180,2,12,30,210,6,2,
%T 2,30,210,6,30,900900,30,180,24,210,60060,210,13860,120,210,210,210,
%U 96,30,60060,6126120,2310,30,60,2310,2310,30,4620,210,240,210,120,30,60,2,1260,30,30,2310,2310,60,18480,30,2310,420,30,2310,18480,30,3360,210,2,420,30
%N Least number with the prime signature of the n-th Wedderburn-Etherington number (A001190).
%H Antti Karttunen, <a href="/A278250/b278250.txt">Table of n, a(n) for n = 1..213</a>
%F a(n) = A046523(A001190(n)).
%o (PARI)
%o {A001190(n) = local(A); if( n<4, n>0, A = vector(n, i, 1); for( i=4, n, A[i] = sum( j=1, (i-1)\2, A[j] * A[i-j]) + if( i%2, 0, A[i/2] * (A[i/2] + 1)/2)); A[n])}; /* _Michael Somos_, Mar 25 2006 */
%o A046523(n) = my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]) \\ _Charles R Greathouse IV_, Aug 17 2011
%o A278250(n) = A046523(A001190(n));
%o for(n=1, 213, write("b278250.txt", n, " ", A278250(n)));
%o (Scheme) (define (A278250 n) (A046523 (A001190 n)))
%Y Cf. A001190, A046523.
%Y Cf. also A278258.
%K nonn
%O 1,4
%A _Antti Karttunen_, Nov 22 2016
|
