

A106323


Smaller of number pair whose squares are reversals of each other, with no leading zeros allowed.


3



12, 13, 33, 102, 103, 112, 113, 122, 1002, 1003, 1011, 1012, 1013, 1021, 1022, 1031, 1102, 1103, 1112, 1113, 1121, 1122, 1202, 1212, 2012, 2022, 3168, 10002, 10003, 10011, 10012, 10013, 10021, 10022, 10031, 10102, 10103, 10111, 10112, 10113
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OFFSET

1,1


COMMENTS

For numbers whose squares are the reversal of a(n)^2, see A106324.


LINKS

Table of n, a(n) for n=1..40.


EXAMPLE

33 is in the sequence because 33^2=1089 and we have 9801=99^2. Likewise,122^2=14884 and we have 48841=221^2.


PROG

(PARI) isok(n) = {if (n % 10 == 0, return (0)); d = digits(n^2, 10); m = sum(k=0, #d1, d[k+1]*10^(k)); if (! issquare(m), return (0)); return (n < sqrtint(m)); } \\ Michel Marcus, Jul 28 2013


CROSSREFS

Cf. A035090; A035123.
Half of A035123.
Sequence in context: A022317 A125998 A307279 * A177796 A322462 A037304
Adjacent sequences: A106320 A106321 A106322 * A106324 A106325 A106326


KEYWORD

base,nonn


AUTHOR

Lekraj Beedassy, Apr 29 2005


EXTENSIONS

Corrected and extended by Joshua Zucker, May 12 2006


STATUS

approved



