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 A152251 #15 Dec 11 2019 09:49:04 %S A152251 1,1,1,2,1,2,4,2,2,5,8,4,4,5,13,16,8,8,10,13,34,32,16,16,20,26,34,89, %T A152251 64,32,32,40,52,68,89,233,128,64,64,80,104,136,178,233,610 %N A152251 Eigentriangle, row sums = A001519, odd-indexed Fibonacci numbers. %C A152251 Row sums = A001519, the odd-indexed Fibonacci numbers starting (1, 2, 5, 13, 34, ...). %C A152251 Sum of n-th row terms = rightmost term of next row. %F A152251 Triangle read by rows, M*Q. M = an infinite lower triangular matrix with (1, 1, 2, 4, 8, 16, ...) in every column and Q = a matrix (1, 1, 2, 5, 13, 34, ...) as the main diagonal and the rest zeros. %F A152251 Let M = production matrix for reversed rows of the triangle as follows: %F A152251 1, 1; %F A152251 1, 0, 2; %F A152251 1, 0, 0, 2; %F A152251 1, 0, 0, 0, 2; %F A152251 1, 0, 0, 0, 0, 2; %F A152251 ... %F A152251 Reversal of n-th row of triangle A152251 = top row terms of M^(n-1). Example: top row of M^3 = (5, 2, 2, 4). - _Gary W. Adamson_, Jul 07 2011 %e A152251 First few rows of the triangle = %e A152251 1; %e A152251 1, 1; %e A152251 2, 1, 2; %e A152251 4, 2, 2, 5; %e A152251 8, 4, 4, 5, 13; %e A152251 16, 8, 8, 10, 13, 34; %e A152251 32, 16, 16, 20, 26, 34, 89; %e A152251 64, 32, 32, 40, 52, 68, 89, 233; %e A152251 128, 64, 64, 80, 104, 136, 178, 233, 610; %e A152251 ... %e A152251 Row 4 = (8, 4, 4, 5, 13) = termwise products of (8, 4, 2, 1, 1) and (1, 1, 2, 5, 13). %Y A152251 Cf. A001519. %K A152251 eigen,nonn,tabl %O A152251 1,4 %A A152251 _Gary W. Adamson_, Nov 30 2008 %E A152251 Last term corrected by _Olivier Gérard_, Aug 11 2016