This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A284046 #7 Mar 19 2017 19:29:56 %S A284046 1,2,3,11,26,111,1111,11111,105462,111111,460688,753576,1111111, %T A284046 2806538,3513626,5858612,11111111,23335688,111111111,674874474, %U A284046 8226042716,2131535935501,81655720279388 %N A284046 Numbers k, not ending in 0, such that the consecutive digits of k^2 differ by 0 or 1. %C A284046 Equivalently, numbers not ending in 0, whose square belong to A032981. %C A284046 All members k ending in 1 are generators of infinite numbers of the form k*10^e which satisfy the same property. In a sense, here we list only "primitive" terms, not ending in 0. %C A284046 a(24) > 10^17, if it exists. %e A284046 81655720279388 belongs to this sequence because the consecutive digits of its square, 6667656654345656676777654544, differ by 0 or 1. %t A284046 Select[Range[10^6], Mod[#, 10] > 0 && Max@ Abs@ Differences@ IntegerDigits[ #^2] <= 1 &] %Y A284046 Cf. A032981, A048412, A079036. %K A284046 nonn,base,more %O A284046 1,2 %A A284046 _Giovanni Resta_, Mar 19 2017