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 A341354 Greatest k such that 3^k divides A156552(2*n); number of trailing 1-digits in the ternary expansion of A156552(n). 4
 0, 1, 0, 0, 2, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 3, 0, 1, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 3, 2, 0, 2, 0, 0, 1, 2, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 1, 2, 0, 0, 0, 4, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 1, 2, 1, 0, 0, 0, 4, 0, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 COMMENTS The 3-adic valuation of A156552(2*n). LINKS Antti Karttunen, Table of n, a(n) for n = 1..65539 FORMULA a(n) = A341353(2*n) = A007949(A156552(2*n)) = A007949(1+(2*A156552(n))). For all n >= 1, a(A000040(2*n)) = a(n^2) = 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 }; A341354(n) = A007949(A156552(2*n)); CROSSREFS Even bisection of A341353. Cf. A000040, A007949, A156552, A341355. Cf. A329604 (positions of nonzero terms). Sequence in context: A057918 A242192 A016380 * A203945 A212663 A341774 Adjacent sequences:  A341351 A341352 A341353 * A341355 A341356 A341357 KEYWORD nonn AUTHOR Antti Karttunen, Feb 14 2021 STATUS approved

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Last modified July 29 17:41 EDT 2021. Contains 346346 sequences. (Running on oeis4.)