A116158 Numbers k such that k concatenated with itself gives the product of two numbers which differ by 5.

6, 96, 150, 186, 324, 376, 666, 996, 2046, 3000, 9996, 82650, 99996, 100384, 466716, 999996, 1322316, 4049584, 9999996, 67820074, 99999996, 110003884, 135734074, 156502836, 196043286, 213017754, 238849000, 261405396

Offset

1,1

Comments

If k has d digits, the concatenation is k//k = 10^d*k+k = m*(m+5), therefore k//k-6 = 10^d*k+k-6 = (m-1)*(m+6), so there is a large overlap with A116119. - R. J. Mathar, May 22 2026

Links

Table of n, a(n) for n=1..28.

Crossrefs

Cf. A116112, A116125, A116159, A116172, A116289.

Sequence in context: A119627 A336825 A376155 * A382384 A275561 A116289

Adjacent sequences: A116155 A116156 A116157 * A116159 A116160 A116161

Keyword

nonn,base,changed

Author

Giovanni Resta, Feb 06 2006

Status

approved