OFFSET
1,2
COMMENTS
As A008477 is not injective and terms A008477(n) are precisely the powerful numbers, this sequence lists the smallest preimage of each powerful number.
There are these three possibilities (see corresponding examples):
EXAMPLE
PROG
(PARI) pwf(n) = my(k=1, nb=1); while (nb != n, k++; if (ispowerful(k), nb++)); k; \\ A001694
f(n) = factorback(factor(n)*[0, 1; 1, 0]); \\ A008477
a(n) = my(k=1, p=pwf(n)); while (f(k) != p, k++); k; \\ Michel Marcus, Mar 28 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Bernard Schott, Mar 27 2021
EXTENSIONS
More terms from Amiram Eldar, Mar 27 2021
STATUS
approved