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A268376 Numbers n for which A001222(n) > A267116(n). 6

%I #14 Feb 05 2016 20:48:16

%S 6,10,14,15,21,22,24,26,30,33,34,35,36,38,39,40,42,46,51,54,55,56,57,

%T 58,60,62,65,66,69,70,72,74,77,78,82,84,85,86,87,88,90,91,93,94,95,96,

%U 100,102,104,105,106,108,110,111,114,115,118,119,120,122,123,126,129,130,132,133,134,135,136,138,140,141

%N Numbers n for which A001222(n) > A267116(n).

%C Numbers n such that in their prime factorization n = p_1^e_1 * ... * p_k^e_k, there is at least one pair of exponents e_i and e_j (i and j distinct), such that their base-2 representations have at least one shared digit-position in which both exponents have 1-bit.

%H Antti Karttunen, <a href="/A268376/b268376.txt">Table of n, a(n) for n = 1..10000</a>

%e n = 6 = 2^1 * 3^1 is included as both exponents, 1 and 1 ("1" in binary) have both 1-bit in position 0 of their binary representations.

%e n = 24 = 2^3 * 3^1 is included as both exponents, 1 and 3 ("01" and "11" in binary) have both 1-bit in position 0 of their binary representations.

%e n = 36 = 2^2 * 3^2 is included as both exponents, 2 and 2 ("10" in binary) have both 1-bit in position 1 of their binary representations.

%e n = 60 = 2^2 * 3^1 * 5^1 is included as the exponents of 3 and 5, both of which are 1, have both 1-bit in position 1 of their binary representations.

%t Select[Range@ 144, PrimeOmega@ # > BitOr @@ Map[Last, FactorInteger@ #] &] (* _Michael De Vlieger_, Feb 04 2016 *)

%o (Scheme, with _Antti Karttunen_'s IntSeq-library)

%o (define A268376 (NONZERO-POS 1 1 A268374))

%Y Cf. A001222, A267116.

%Y Indices of nonzeros in A268374.

%Y Subsequence of A002808 and A024619.

%Y Cf. A268375 (complement).

%Y Cf. A260730 (subsequence).

%Y Cf. also A267117.

%Y Differs from A067582(n+1) for the first time at n=25, where a(n) = 60, a value which is missing from A067582.

%K nonn,base

%O 1,1

%A _Antti Karttunen_, Feb 03 2016

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Last modified April 25 03:15 EDT 2024. Contains 371964 sequences. (Running on oeis4.)