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Positions of ones in A231717.
4

%I #11 Nov 27 2013 05:11:20

%S 1,8,14,18,22,33,37,41,45,53,57,61,71,75,87,116,120,124,128,136,140,

%T 144,154,158,170,208,212,216,226,230,242,289,293,305,362,544,548,552,

%U 556,564,568,572,582,586,598,636,640,644,654,658,670,717,721,733,790,1021

%N Positions of ones in A231717.

%C This sequence gives all n at which positions the successive terms A219666(n-1) & A219666(n) in the infinite trunk of the factorial beanstalk differ only in one digit position in their factorial base representations (A007623) and the difference of those digits is exactly one.

%H Antti Karttunen, <a href="/A231718/b231718.txt">Table of n, a(n) for n = 1..11905</a>

%F For all n, A230406(a(n)) = A000142(A231719(a(n))).

%e 14 is included, because A219666(13) = 40 = '1220' in factorial base representation, while A219666(14) = 46 = '1320' in factorial base, and they differ only by the third least significant digits, and 3-2 = 1.

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

%o (define A231718 (MATCHING-POS 1 1 (lambda (i) (= 1 (A231717 i)))))

%Y Subset of A230422.

%K nonn

%O 1,2

%A _Antti Karttunen_, Nov 12 2013