A116177 Numbers k such that k concatenated with k+3 gives the product of two numbers which differ by 2.

205, 300, 477, 732, 1920, 3157, 52896, 120085, 427020, 8264460, 88581312, 112000885, 112917765, 143075580, 152863360, 193537077, 233788192, 266755221, 313680096, 370908477, 386568925, 440852992, 442670220

Offset

1,1

Comments

If k+3 has d digits, the concatenation is k//k+3 = 10^d*k+k+3 = m*(m+2), therefore k//k+4 = 10^d*k+k+4 = (m+1)^2, so there is a large overlap with A115437. - R. J. Mathar, May 22 2026

Links

Table of n, a(n) for n=1..23.

Crossrefs

Cf. A115426, A116099, A116112, A115428, A116308.

Sequence in context: A270605 A072573 A249052 * A191834 A042983 A186475

Adjacent sequences: A116174 A116175 A116176 * A116178 A116179 A116180

Keyword

nonn,base,changed

Author

Giovanni Resta, Feb 06 2006

Status

approved