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A278244
Least number with the prime signature of the n-th centered square number (A001844(n)).
2
1, 2, 2, 4, 2, 2, 6, 2, 6, 2, 6, 6, 2, 6, 2, 6, 6, 2, 6, 2, 4, 12, 2, 30, 2, 2, 6, 6, 24, 2, 2, 6, 2, 6, 2, 2, 30, 6, 6, 2, 6, 30, 2, 6, 6, 6, 12, 2, 6, 12, 2, 6, 6, 12, 6, 6, 6, 6, 12, 6, 2, 30, 6, 6, 6, 2, 30, 6, 6, 2, 2, 12, 2, 6, 6, 6, 6, 6, 60, 2, 6, 6, 2, 6, 2, 2, 30, 2, 30, 6, 2, 30, 6, 30, 6, 30, 24, 2, 6, 2, 2, 30, 2, 12, 2, 6, 30, 6, 30, 2, 2, 6, 6, 6, 6
OFFSET
0,2
LINKS
FORMULA
a(n) = A046523(A001844(n)).
PROG
(PARI)
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
A001844(n) = 2*((n^2) + n) + 1;
for(n=0, 10000, write("b278244.txt", n, " ", A278244(n)));
(Scheme) (define (A278244 n) (A046523 (A001844 n)))
CROSSREFS
Cf. also A278162, A278254, A278259.
Sequence in context: A175462 A133946 A286250 * A278542 A033722 A320166
KEYWORD
nonn
AUTHOR
Antti Karttunen, Nov 22 2016
STATUS
approved