login
A262873
Predestined numbers A262743 in which every term is generated by at least one pair of products where all (and only those) first product's factor's digits are, in reverse order, the same as those of the second two factors.
3
504, 756, 806, 868, 1008, 1148, 1176, 1209, 1472, 1475, 1512, 1638, 1708, 2016, 2184, 2208, 2418, 2548, 2730, 2772, 2924, 3024, 3388, 4416
OFFSET
1,1
COMMENTS
In this sequence, the position of the multiplication sign in the reversed order is irrelevant, so, e.g., 11088 (48*231 and 132*84), 1176 (4*294 and 49*24) and 2548 (4*637 and 7*364) are in the sequence.
REFERENCES
Francesco Di Matteo, Sequenze ludiche, Game Edizioni (2015), page 34.
LINKS
Francesco Di Matteo, Table of n, a(n) for n = 1..132
Algebra.com, Question 265287
A. Marchini and F. Di Matteo, All the first 132 terms calculated
Math Forum at Drexel, Reversing the Digits
EXAMPLE
504 = 12*42 = 24*21;
756 = 12*63 = 36*21;
806 = 13*62 = 26*31;
868 = 4*217 = 7*124;
1008 = 12*84 = 48*21;
1148 = 14*82 = 28*41;
1176 = 4*294 = 49*24, etc.
CROSSREFS
Subsequence of A262743.
Cf. A228164 (contains only symmetrical digits' factors)
Sequence in context: A066525 A043304 A045212 * A228164 A060666 A335654
KEYWORD
nonn,base
AUTHOR
Francesco Di Matteo, Oct 03 2015
STATUS
approved