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Numbers k such that k*(k+5) gives the concatenation of a number m with itself.
5

%I #13 Jul 18 2021 05:31:51

%S 6,96,385,429,567,611,814,996,4521,5475,9996,90910,99996,316832,

%T 683164,999996,3636364,6363632,9999996,82352942,99999996,331668332,

%U 368421053,395604391,442767754,461538462,488721800,511278196

%N Numbers k such that k*(k+5) gives the concatenation of a number m with itself.

%Y Cf. A028557, A020338.

%Y Cf. A116158, A116281, A116288, A116290, A116303.

%K nonn,base

%O 1,1

%A _Giovanni Resta_, Feb 06 2006