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 A061099 #32 Jul 15 2024 15:32:37 %S A061099 1,64,100,289,361,676,784,1225,1369,1936,2116,2809,3025,3844,4096, %T A061099 5041,5329,6400,6724,7921,8281,9604,10000,11449,11881,13456,13924, %U A061099 15625,16129,17956,18496,20449,21025,23104,23716,25921,26569,28900,29584 %N A061099 Squares with digital root 1. %H A061099 Harry J. Smith, <a href="/A061099/b061099.txt">Table of n, a(n) for n = 1..1001</a> %H A061099 Amarnath Murthy & Charles Ashbacher, <a href="http://fs.gallup.unm.edu/murthybook.pdf">Fabricating a perfect square with a given valid digit sum</a>, in Generalized Partitions and New Ideas On Number Theory and Smarandache Sequences, pp 154-156. %H A061099 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,2,-2,-1,1). %F A061099 From _Colin Barker_, Apr 21 2012: (Start) %F A061099 a(n) = (9*n+2)^2/4 for n even; a(n)=(9*n+7)^2/4 for n odd. %F A061099 G.f.: x*(1+63*x+34*x^2+63*x^3+x^4)/((1-x)^3*(1+x)^2). (End) %F A061099 a(n) = a(n-1)+2*a(n-2)-2*a(n-3)-a(n-4)+a(n-5). - _Wesley Ivan Hurt_, Apr 21 2021 %e A061099 289 = 17^2, 2+8+9 = 19, 1+9 = 1, 1369 = 37^2, 1+3+6+9 = 19, 1+9 = 1. %o A061099 (PARI) a(n)=(n\2*9-(-1)^n)^2 \\ _Charles R Greathouse IV_, Sep 20 2012 %Y A061099 Squares of A056020. %Y A061099 Cf. A056991. %K A061099 nonn,base,easy %O A061099 1,2 %A A061099 _Amarnath Murthy_, Apr 19 2001 %E A061099 More terms from _Harry J. Smith_, Jul 17 2009