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 A341353 Greatest k such that 3^k divides A156552(n); the 3-adic valuation of A156552(n). 3
 0, 0, 1, 0, 0, 0, 0, 1, 2, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 3, 0, 0, 1, 1, 0, 0, 0, 0, 0, 3, 0, 0, 1, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 0, 0, 1, 0, 2, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 3, 3, 0, 2, 2, 0, 0, 2, 0, 0, 0, 0, 0, 1, 0, 2, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,9 LINKS Antti Karttunen, Table of n, a(n) for n = 2..65539 FORMULA a(n) = A007949(A156552(n)). a(p) = 0 for all primes p. a(n^2) > 0 for all n >= 2. a(n) > 0 iff A329903(n) = 0. PROG (PARI) A007949(n) = valuation(n, 3); A156552(n) = { my(f = factor(n), 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 }; A341353(n) = A007949(A156552(n)); CROSSREFS Cf. A007949, A156552, A329609 (positions of nonzeros), A329903, A341354 (even bisection), A341355. Cf. also A055396 (the 2-adic valuation + 1), A292251. Sequence in context: A080224 A341508 A261488 * A010105 A341618 A337690 Adjacent sequences:  A341350 A341351 A341352 * A341354 A341355 A341356 KEYWORD nonn AUTHOR Antti Karttunen, Feb 14 2021 STATUS approved

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Last modified August 2 09:22 EDT 2021. Contains 346422 sequences. (Running on oeis4.)