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%I #32 Jan 09 2025 10:15:33
%S 2,3,2,4,2,5,3,6,2,3,5,7,2,4,8,4,9,2,3,5,7,10,2,3,5,11,5,6,12,2,3,4,6,
%T 9,13,2,3,4,7,11,14,3,7,15,2,4,5,8,10,11,16,2,5,7,8,17,3,4,6,7,9,14,
%U 18,2,3,4,6,9,13,19
%N Irregular triangle read by rows: row n gives list of nontrivial reverse multipliers for base n.
%C If there is a number m such that the reversal of m in base n is c times m, then c is called a reverse multiplier for n. For example, 2 is a reverse multiplier for base n=5, since 8 (base 10) = 13 (base 5), and 2*8 = 16 (base 10) = 31 (base 5).
%C The trivial reverse multiplier 1 is excluded.
%C The last entry in each row is n-1; the number of terms in row n is A222819(n).
%H N. J. A. Sloane, <a href="/A222817/a222817.txt">Table giving n, list of nontrivial reverse multipliers, for n = 3..100</a>
%H N. J. A. Sloane, <a href="http://arxiv.org/abs/1307.0453">2178 And All That</a>, arXiv:1307.0453 [math.NT], 2013; Fib. Quart., 52 (2014), 99-120.
%H N. J. A. Sloane, <a href="/A001232/a001232.pdf">2178 And All That</a> [Local copy]
%H Anne Ludington Young, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/30-2/ludington1.pdf">k-Reverse multiples</a>, Fib. Q., 30 (1992), 126-132.
%e Triangle begins:
%e 2,
%e 3,
%e 2,4,
%e 2,5,
%e 3,6,
%e 2,3,5,7,
%e 2,4,8,
%e 4,9,
%e 2,3,5,7,10,
%e 2,3,5,11,
%e 5,6,12,
%e 2,3,4,6,9,13,
%e 2,3,4,7,11,14,
%e 3,7,15,
%e ...
%Y Cf. A214927, A222818, A222819, A222820.
%Y See A214927 for other cross-references.
%K nonn,tabf
%O 3,1
%A _N. J. A. Sloane_, Mar 13 2013