A116279 Numbers k such that k*(k+2) gives the concatenation of two numbers m and m-1.

36363636363, 45454545454, 54545454545, 63636363636, 72727272727, 81818181818, 90909090909, 428571428571428571428, 571428571428571428571, 714285714285714285714, 857142857142857142857

Offset: 1

Author

Giovanni Resta, Feb 06 2006

Keywords

• nonn
• base

Examples

			36363636363 * 36363636365 = 13223140496//13223140495, where // denotes concatenation.
		

Crossrefs

Cf. A102567, A116273, A116280, A116286.