

A110404


Least multiple of n which is a repeated reverse concatenation of digits of n where n == 1, 3, 7 or 9 (mod 10).


1



1, 3, 7, 9, 11, 313131, 7171717171717171, 919191919191919191, 121212, 3232323232323232323232, 727272, 9292929292929292929292929292, 131313131313131313131313131313, 33, 737373, 939393, 1414141414
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..17.


EXAMPLE

For 13 the term is 313131 as 313131 = 13*24087.


MATHEMATICA

f[n_] := Block[{k = 1, id = Reverse[ IntegerDigits[n]]}, While[fd = FromDigits[ Flatten[ Table[id, {k}]]]; Mod[fd, n] != 0, k++ ]; fd]; lst = Select[ Range[1, 41, 2], Mod[ #, 5] != 0 &]; f /@ lst (* Robert G. Wilson v *)


CROSSREFS

Cf. A110405.
Sequence in context: A114788 A085074 A175637 * A190366 A342699 A284819
Adjacent sequences: A110401 A110402 A110403 * A110405 A110406 A110407


KEYWORD

base,easy,nonn


AUTHOR

Amarnath Murthy, Jul 30 2005


EXTENSIONS

More terms from Robert G. Wilson v, Jul 30 2005


STATUS

approved



