

A085869


Numbers n such that n and its digit reversal have the same prime signature.


5



1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 15, 17, 22, 26, 31, 33, 37, 39, 44, 51, 55, 58, 62, 66, 71, 73, 77, 79, 85, 88, 93, 97, 99, 101, 107, 111, 113, 115, 117, 121, 122, 123, 129, 131, 141, 143, 149, 151, 155, 157, 158, 159, 161, 165, 167, 169, 171, 177, 178, 179, 181
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OFFSET

1,2


LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..20000


EXAMPLE

15 is a member 15 = 3*5 and 51 = 3*17 both have the prime signature p*q, p and q are primes.


MAPLE

s:= n> sort(map(i> i[2], ifactors(n)[2])):
a:= proc(n) option remember; local k; for k from 1+a(n1) while
s(k)<>s((p> parse(cat(seq(p[i], i=1..length(p)))))(""k)) do od; k
end: a(0):=0:
seq(a(n), n=1..80); # Alois P. Heinz, Mar 09 2018


CROSSREFS

Cf. A062895.
Sequence in context: A289351 A171550 A062895 * A068892 A106801 A242417
Adjacent sequences: A085866 A085867 A085868 * A085870 A085871 A085872


KEYWORD

base,easy,nonn


AUTHOR

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jul 06 2003


EXTENSIONS

Corrected and extended by Ray Chandler, Aug 08 2003


STATUS

approved



