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 A340683 a(n) = A007949((A003961(A003961(n))+1)/2), where A003961 shifts the prime factorization of n one step towards larger primes, and A007949(x) gives the exponent of largest power of 3 dividing x. 2
 0, 1, 0, 0, 1, 2, 0, 2, 0, 0, 2, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 2, 0, 0, 0, 0, 0, 1, 1, 3, 1, 3, 1, 1, 0, 0, 1, 4, 0, 0, 1, 0, 1, 1, 1, 0, 2, 2, 0, 0, 0, 1, 0, 0, 2, 0, 0, 0, 1, 1, 3, 0, 1, 1, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 1, 0, 2, 1, 0, 3, 0, 0, 3, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,6 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65537 Index entries for sequences computed from indices in prime factorization FORMULA a(n) = A292251(A003961(n)) = A007949(A048673(A003961(n))). PROG (PARI) A003961(n) = { my(f=factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); factorback(f); }; \\ From A003961 A340683(n) = valuation((A003961(A003961(n))+1)/2, 3); CROSSREFS Cf. A003961, A007949, A048673, A292251, A341347. Sequence in context: A035220 A227618 A366533 * A221645 A216176 A359007 Adjacent sequences: A340680 A340681 A340682 * A340684 A340685 A340686 KEYWORD nonn AUTHOR Antti Karttunen, Feb 14 2021 STATUS approved

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Last modified September 15 10:23 EDT 2024. Contains 375932 sequences. (Running on oeis4.)