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URL: https://oeis.org/A347119

⇱ A347119 - OEIS

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A347119
Squarefree part of A005940(1+(3*A156552(n))): a(n) = A007913(A332449(n)).
3
1, 1, 1, 10, 1, 1, 1, 30, 21, 1, 1, 22, 1, 1, 1, 10, 1, 10, 1, 10, 1, 1, 1, 66, 55, 1, 105, 10, 1, 1, 1, 30, 1, 1, 1, 154, 1, 1, 1, 30, 1, 1, 1, 10, 39, 1, 1, 22, 91, 21, 1, 10, 1, 30, 1, 30, 1, 1, 1, 34, 1, 1, 21, 10, 1, 1, 1, 10, 1, 1, 1, 462, 1, 1, 21, 10, 1, 1, 1, 10, 21, 1, 1, 22, 1, 1, 1, 30, 1, 22, 1, 10
OFFSET
1,4
FORMULA
a(n) = A007913(A332449(n)).
a(n) = A332449(n) / A000290(A347120(n)).
PROG
(PARI)
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A156552(n) = { my(f = factor(n), p, p2 = 1, res = 0); for(i = 1, #f~, p = 1 << (primepi(f[i, 1]) - 1); res += (p * p2 * (2^(f[i, 2]) - 1)); p2 <<= f[i, 2]); res };
A332449(n) = A005940(1+(3*A156552(n)));
A347119(n) = core(A332449(n));
CROSSREFS
Cf. A000290, A005117 (positions of 1's), A005940, A007913, A156552, A332449, A347120.
Sequence in context: A010178 A070596 A306363 * A010177 A096089 A010176
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 22 2021
STATUS
approved