A116281 - OEIS

%I #13 Jul 18 2021 06:46:58

%S 39,57,32262231,67737765,79321055,3341093417798787499092,

%T 3861488851737861033960,4747922651210186579786,5252077348789813420210,

%U 6138511148262138966036,6658906582201212500904,7232275368591793618230

%N Numbers k such that k*(k+5) gives the concatenation of two numbers m and m-1.

%e 79321055 * 79321060 = 62918301//62918300, where // denotes concatenation.

%Y Cf. A028557, A116112, A116276, A116280, A116282, A116289.

%K nonn,base

%O 1,1

%A _Giovanni Resta_, Feb 06 2006