A116205 Numbers k such that k concatenated with k+7 gives the product of two numbers which differ by 3.

1, 81, 1353, 3997, 7723, 23761, 26271, 76771, 1415683, 3890571, 8495497, 1066870443, 1239366513, 4198438981, 4534273891, 6502317141, 6918679731, 2199164200036329043, 2820114781174460091, 5500888421709400741

Offset: 1

Author

Giovanni Resta, Feb 06 2006

Keywords

• nonn
• base

Comments

Also numbers k such that k concatenated with k+9 gives the product of two numbers which differ by 1.

Also numbers k such that k concatenated with k-3 gives the product of two numbers which differ by 7.

Crossrefs

Cf. A116179, A116172, A115429, A116173, A116193, A116336.

Cf. A116132, A116099, A116139, A116152, A116269, A116348.

Extensions

Edited by N. J. A. Sloane, Apr 13 2007