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A115429 Numbers k such that the concatenation of k with k+8 gives a square. 25

%I

%S 6001,6433,11085116,44496481,96040393,115916930617,227007035017,

%T 274101929528,434985419768,749978863753,996004003993,1365379857457948,

%U 1410590590957816,1762388551055953,2307340946901148,2700383162251217

%N Numbers k such that the concatenation of k with k+8 gives a square.

%C Also numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 2.

%C Also numbers k such that k concatenated with k+4 gives the product of two numbers which differ by 4.

%C Also numbers k such that k concatenated with k-1 gives the product of two numbers which differ by 6.

%C Also numbers k such that k concatenated with k-8 gives the product of two numbers which differ by 8.

%e 6001//6009 = 7747^2, where // denotes concatenation.

%e 96040393//96040400 = 98000200 * 98000202.

%e 96040393//96040397 = 98000199 * 98000203.

%e 96040393//96040392 = 98000198 * 98000204.

%Y Cf. A030465, A102567, A115426, A115437, A115428, A115430, A115431, A115432, A115433, A115434, A115435, A115436, A115440.

%Y Cf. A116107, A116109, A116113, A116239.

%Y Cf. A116205, A115430, A116335, A116185, A116187, A116317.

%Y Cf. A116131, A116112, A116152, A116159, A116282.

%K base,nonn

%O 1,1

%A _Giovanni Resta_, Jan 24 2006

%E Edited by _N. J. A. Sloane_, Apr 15 2007

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Last modified August 6 00:46 EDT 2021. Contains 346493 sequences. (Running on oeis4.)