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A222818
Irregular triangle read by rows: row n gives list of reverse multipliers for base n.
4
1, 1, 2, 1, 3, 1, 2, 4, 1, 2, 5, 1, 3, 6, 1, 2, 3, 5, 7, 1, 2, 4, 8, 1, 4, 9, 1, 2, 3, 5, 7, 10, 1, 2, 3, 5, 11, 1, 5, 6, 12, 1, 2, 3, 4, 6, 9, 13, 1, 2, 3, 4, 7, 11, 14, 1, 3, 7, 15, 1, 2, 4, 5, 8, 10, 11, 16, 1, 2, 5, 7, 8, 17, 1, 3, 4, 6, 7, 9, 14, 18, 1, 2, 3, 4, 6, 9, 13, 19
OFFSET
2,3
COMMENTS
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).
The trivial reverse multiplier 1 is included.
The last entry in each row is n-1; the number of terms in row n is A222820(n).
REFERENCES
For a complete list of references and links related to this problem see A214927.
LINKS
N. J. A. Sloane, 2178 And All That, arXiv:1307.0453 [math.NT], 2013; Fib. Quart., 52 (2014), 99-120.
Anne Ludington Young, k-Reverse multiples, Fib. Q., 30 (1992), 126-132.
EXAMPLE
Triangle begins:
1,
1,2,
1,3,
1,2,4,
1,2,5,
1,3,6,
1,2,3,5,7,
1,2,4,8,
1,4,9,
1,2,3,5,7,10,
1,2,3,5,11,
1,5,6,12,
1,2,3,4,6,9,13,
1,2,3,4,7,11,14,
1,3,7,15
...
CROSSREFS
See A214927 for other cross-references.
Sequence in context: A301983 A373889 A165416 * A057059 A368313 A346795
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Mar 13 2013
STATUS
approved