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 A143929 #22 Feb 01 2025 08:41:37 %S A143929 1,2,1,3,2,3,4,3,6,8,5,4,9,16,21,6,5,12,24,42,55,7,6,15,32,63,110,144, %T A143929 8,7,18,40,84,165,288,377,9,8,21,48,105,220,432,754,987,10,9,24,56, %U A143929 126,275,576,1131,1974,2584 %N A143929 Eigentriangle by rows, termwise products of the natural numbers decrescendo and the bisected Fibonacci series. %C A143929 Row sums = even-indexed Fibonacci terms A001906. %C A143929 Sum of n-th row terms = rightmost term of next row. %F A143929 Given A004736: (1; 2,1; 3,2,1; 4,3,2,1; ...), we apply the termwise products of the sequence {A088305(n-1)}_{n>=1} starting (1, 1, 3, 8, 21, ...). %F A143929 From _Wolfdieter Lang_, Jan 07 2021: (Start) %F A143929 T(n, m) = 0 if n < m; T(n, 1) = n, for n >= 1, and T(n, m) = F(2*(m-1))*(n-m+1) for n >= m >= 2, with F = A000045 (Fibonacci). %F A143929 G.f. column m: G(1, x) = x/(1-x)^2, G(m, x) = F(2*(m-1))*x^m/(1-x)^2, for m >= 2. (End) %F A143929 With offset 0: g.f. of row polynomials R(n, x) := Sum_{m=0..n} t(n, m)*x^m, that is, g.f. of triangle t(n,m) = T(n+1, m+1): %F A143929 G(z, x) = (1 - x*z)^2 / ((1 - z)^2*(1 - 3*x*z + (x*z)^2)). - _Wolfdieter Lang_, Apr 09 2021 %e A143929 First rows of the triangle T(n, m), n >= 1, m = 1..n: %e A143929 1; %e A143929 2, 1; %e A143929 3, 2, 3; %e A143929 4, 3, 6, 8; %e A143929 5, 4, 9, 16, 21; %e A143929 6, 5, 12, 24, 42, 55; %e A143929 7, 6, 15, 32, 63, 110, 144; %e A143929 8, 7, 18, 40, 84, 165, 288, 377; %e A143929 9, 8, 21, 48, 105, 220, 432, 754, 987; %e A143929 ... %e A143929 Example: row 4 = (4, 3, 6, 8) = termwise product of (4, 3, 2, 1) and (1, 1, 3, 8). %Y A143929 Cf. A000045, A001906, A004736, A088305. %K A143929 nonn,easy,tabl %O A143929 1,2 %A A143929 _Gary W. Adamson_, Sep 05 2008