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A359600
The least odd number with the same prime signature as n.
2
1, 3, 3, 9, 3, 15, 3, 27, 9, 15, 3, 45, 3, 15, 15, 81, 3, 45, 3, 45, 15, 15, 3, 135, 9, 15, 27, 45, 3, 105, 3, 243, 15, 15, 15, 225, 3, 15, 15, 135, 3, 105, 3, 45, 45, 15, 3, 405, 9, 45, 15, 45, 3, 135, 15, 135, 15, 15, 3, 315, 3, 15, 45, 729, 15, 105, 3, 45, 15, 105, 3, 675, 3, 15, 45, 45, 15, 105, 3, 405, 81
OFFSET
1,2
FORMULA
a(n) = A003961(A046523(n)).
MAPLE
a:= n-> (l-> mul(ithprime(i+1)^l[i][2], i=1..nops(l)))
(sort(ifactors(n)[2], (x, y)->x[2]>y[2])):
seq(a(n), n=1..100); # Alois P. Heinz, Jan 12 2023
PROG
(PARI) a(n) = { my(f=vecsort(factor(n)[, 2], , 4)); prod(i=1, #f, prime(i+1)^f[i]) } \\ Andrew Howroyd, Jan 12 2023
(Python)
from math import prod
from sympy import prime, factorint
def A359600(n): return prod(prime(i)**e for i, e in enumerate(sorted(factorint(n).values(), reverse=True), 2)) # Chai Wah Wu, Jan 12 2023
CROSSREFS
Cf. also A278223.
Sequence in context: A217883 A036553 A339318 * A166466 A068219 A337461
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 12 2023
STATUS
approved