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A306992 Lexicographically earliest sequence of distinct positive terms such that the product of two consecutive terms is digitally balanced. 2

%I #11 Mar 21 2019 13:28:32

%S 1,2,5,7,6,25,9,15,10,17,12,13,4,3,14,11,18,31,19,29,8,23,26,22,40,63,

%T 33,69,36,67,34,21,99,27,30,82,28,81,35,61,16,47,50,53,48,73,37,20,41,

%U 56,45,49,43,52,51,42,54,46,55,44,57,38,65,127,66,135,70

%N Lexicographically earliest sequence of distinct positive terms such that the product of two consecutive terms is digitally balanced.

%C Digitally balanced numbers correspond to A031443.

%C This sequence has similarities with A269361.

%H Rémy Sigrist, <a href="/A306992/b306992.txt">Table of n, a(n) for n = 1..10000</a>

%H Rémy Sigrist, <a href="/A306992/a306992.gp.txt">PARI program for A306992</a>

%e The first terms, alongside the binary representation of a(n)*a(n+1), are:

%e n a(n) bin(a(n)*a(n+1))

%e -- ---- ----------------

%e 1 1 10

%e 2 2 1010

%e 3 5 100011

%e 4 7 101010

%e 5 6 10010110

%e 6 25 11100001

%e 7 9 10000111

%e 8 15 10010110

%e 9 10 10101010

%e 10 17 11001100

%e 11 12 10011100

%e 12 13 110100

%e 13 4 1100

%e 14 3 101010

%e 15 14 10011010

%e 16 11 11000110

%o (PARI) See Links section.

%Y See A306994 for the additive variant.

%Y Cf. A031443, A269361.

%K nonn,look,base

%O 1,2

%A _Rémy Sigrist_, Mar 18 2019

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Last modified June 19 18:58 EDT 2024. Contains 373507 sequences. (Running on oeis4.)