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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

Index entries for sequences computed from indices in prime factorization

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.)