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 A107677 #4 Mar 31 2012 10:26:04 %S A107677 8,89,98,406,593,998,4445,4544,5455,5554,9899,9998,34687,44443,55556, %T A107677 65312,90242,99998,219374,285713,286714,296297,297296,340066,362636, %U A107677 363637,374219,416989,583010,625780,636362,637363,659933,702703,703702 %N A107677 Numbers A such that the square of concatenation AA is of form NNMM. %C A107677 N and M must be of equal length, leading zeros are allowed. The corresponding values NM are in A107678. %e A107677 593 is in the sequence because we have 593593^2 = 352352649649; 998 is in the sequence since 998998^2 = 997997004004 (M has two leading zeros); 219374 is in the sequence since 219374219374^2 = 48125048125951876951876 (N has one leading zero). %Y A107677 Cf. A107678, A106497. %K A107677 nonn,base %O A107677 1,1 %A A107677 _Lekraj Beedassy_, May 20 2005 %E A107677 Edited, corrected and extended by _Klaus Brockhaus_, May 22 2005