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 A086404 #7 May 23 2021 02:39:33 %S A086404 1,1,1,1,2,3,1,3,6,3,1,4,11,16,9,1,5,18,41,44,9,1,6,27,84,153,120,27, %T A086404 1,7,38,151,396,571,328,27,1,8,51,248,857,1872,2131,896,81,1,9,66,381, %U A086404 1644,4893,8856,7953,2448,81,1,10,83,556,2889,10984,28003,41904,29681 %N A086404 Square array of numbers T(n,k) = ((1+sqrt(3))*(k+sqrt(3))^n-(1-sqrt(3))*(k-sqrt(3))^n)/(2*sqrt(3)), read by antidiagonals. %e A086404 Rows begin %e A086404 1, 1, 3, 3, 9, ... %e A086404 1, 2, 6, 16, 44, ... %e A086404 1, 3, 11, 41, 153, ... %e A086404 1, 4, 18, 84, 396, ... %e A086404 1, 5, 27, 151, 857, ... %Y A086404 Rows include A002605, A079935, A086405. Main diagonal is A086406. Rows are successive binomial transforms of (1, 1, 3, 3, 9, 9, ...). %Y A086404 Cf. A086350. %K A086404 easy,nonn,tabl %O A086404 0,5 %A A086404 _Paul Barry_, Jul 19 2003