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A365425
The least number with the prime signature of the odd part of A163511(n): a(n) = A046523(A000265(A163511(n))).
7
1, 1, 1, 2, 1, 4, 2, 2, 1, 8, 4, 4, 2, 6, 2, 2, 1, 16, 8, 8, 4, 12, 4, 4, 2, 12, 6, 6, 2, 6, 2, 2, 1, 32, 16, 16, 8, 24, 8, 8, 4, 36, 12, 12, 4, 12, 4, 4, 2, 24, 12, 12, 6, 30, 6, 6, 2, 12, 6, 6, 2, 6, 2, 2, 1, 64, 32, 32, 16, 48, 16, 16, 8, 72, 24, 24, 8, 24, 8, 8, 4, 72, 36, 36, 12, 60, 12, 12, 4, 36, 12, 12, 4, 12, 4, 4, 2
OFFSET
0,4
LINKS
FORMULA
For all n >= 1, a(n) = a(2*n) = a(A000265(n)).
PROG
(PARI)
A000265(n) = (n>>valuation(n, 2));
A046523(n) = { my(f=vecsort(factor(n)[, 2], , 4), p); prod(i=1, #f, (p=nextprime(p+1))^f[i]); }; \\ From A046523
A163511(n) = if(!n, 1, my(p=2, t=1); while(n>1, if(!(n%2), (t*=p), p=nextprime(1+p)); n >>= 1); (t*p));
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Sep 03 2023
STATUS
approved