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Numbers k such that k*(k+3) gives the concatenation of a number m with itself.

5

`%I #9 Jul 18 2021 02:56:22
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`%S 8,98,767,858,910,998,3285,6713,9998,45452,54546,99998,990100,999998,
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`%T 8181819,9999998,70588233,99999998,343130554,362637363,363636361,
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`%U 420053631,421052632,497975709,502024289,578947366,579946367
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`%N Numbers k such that k*(k+3) gives the concatenation of a number m with itself.
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`%Y Cf. A116130, A116280, A116286, A116288, A116296.
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`%K nonn,base
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`%O 1,1
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`%A _Giovanni Resta_, Feb 06 2006
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