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 A046645 a(n) = log_2(A046644(n)); also the 2-adic valuation of A046644(n). 20
 0, 1, 1, 3, 1, 2, 1, 4, 3, 2, 1, 4, 1, 2, 2, 7, 1, 4, 1, 4, 2, 2, 1, 5, 3, 2, 4, 4, 1, 3, 1, 8, 2, 2, 2, 6, 1, 2, 2, 5, 1, 3, 1, 4, 4, 2, 1, 8, 3, 4, 2, 4, 1, 5, 2, 5, 2, 2, 1, 5, 1, 2, 4, 10, 2, 3, 1, 4, 2, 3, 1, 7, 1, 2, 4, 4, 2, 3, 1, 8, 7, 2, 1, 5, 2, 2, 2, 5, 1, 5, 2, 4, 2 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS A268375 gives numbers n for which a(n) = A289617(n) = A005187(A001222(n)). - Antti Karttunen, Jul 08 2017 LINKS Antti Karttunen, Table of n, a(n) for n = 1..65536 FORMULA a(n) = A007814(A046644(n)). - Michel Marcus, Apr 16 2015 Additive with a(p^n) = A005187(n). - Antti Karttunen, Jul 08 2017 a(n) = A293447(A293442(n)). - Antti Karttunen, Nov 10 2017 PROG (PARI) A007814(n) = (valuation(n, 2)); A046643perA046644(n) = { my(c=1); if(1==n, c, fordiv(n, d, if((d>1)&&(d>=1, s+=n); s; }; A046645(n) = vecsum(apply(e -> A005187(e), factorint(n)[, 2])); \\ A faster implementation. - Antti Karttunen, Jul 08 2017 CROSSREFS See A046643, A046644 for more details. Cf. A001222, A005187, A007814, A268375, A289617, A289618, A293442, A293447. Sequence in context: A257980 A203531 A324885 * A284639 A320887 A295923 Adjacent sequences:  A046642 A046643 A046644 * A046646 A046647 A046648 KEYWORD nonn AUTHOR STATUS approved

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Last modified May 26 13:49 EDT 2020. Contains 334626 sequences. (Running on oeis4.)