A115537 Numbers k such that the concatenation of 4*k with k gives a square.

17728531856, 27700831025, 39889196676, 54293628809, 70914127424, 89750692521, 32653061224489796, 73469387755102041, 1245674740484429065743944636678200692041522491349481

Offset: 1

Author

Giovanni Resta, Jan 25 2006

Keywords

• nonn
• base

Examples

			70914127424_17728531856 = 84210526316^2.
		

Crossrefs

Cf. A102567, A106497, A115527 - A115556.