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A115741 Semiprimes (A001358) whose digit reversal is a triangular number. 1
6, 10, 51, 55, 82, 87, 309, 501, 649, 694, 1198, 1207, 1473, 1765, 1803, 1837, 1959, 1981, 3043, 3057, 3561, 3574, 5158, 5221, 5721, 6139, 6193, 6267, 6535, 6711, 6814, 6843, 10473, 10497, 11553, 12477, 12693, 13123, 13701, 13951, 14169 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
51=3*17 is semiprime and 15=T(5).
CROSSREFS
Sequence in context: A346501 A115917 A275004 * A177168 A136843 A219776
KEYWORD
nonn,base
AUTHOR
Giovanni Resta, Jan 31 2006
STATUS
approved

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Last modified May 20 19:00 EDT 2024. Contains 372720 sequences. (Running on oeis4.)