cp's OEIS Frontend

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.

A231729 Triangular array read by rows: row n shows the coefficients of the polynomial u(n) = c(0) + c(1)*x + ... + c(2n-1)*x^(2n-1) which is the denominator of the n-th convergent of the continued fraction [k, k, k, ... ], where k = (x^2 + 1)/(x + 1).

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%I A231729 #5 Nov 02 2014 12:18:36
%S A231729 1,1,1,1,1,1,2,4,5,3,1,1,3,7,11,11,9,5,1,1,5,15,29,35,32,22,13,7,1,1,
%T A231729 8,28,62,90,103,91,65,37,17,9,1,1,13,53,134,226,296,302,257,183,110,
%U A231729 56,21,11,1,1,21,97,273,521,775,915,903,743,523,319,167
%N A231729 Triangular array read by rows: row n shows the coefficients of the polynomial u(n) = c(0) + c(1)*x + ... + c(2n-1)*x^(2n-1) which is the denominator of the n-th convergent of the continued fraction [k, k, k, ... ], where k = (x^2 + 1)/(x + 1).
%C A231729 Sum of numbers in row n:  2*A063727(n).  Left edge:  A000045 (Fibonacci numbers).
%e A231729 First 3 rows:
%e A231729 1 . . . 1
%e A231729 1 . . . 1 . . . 1 . . . 1
%e A231729 2 . . . 4 . . . 5 . . . 3 . . . 1 . . . 1 . . . 1
%e A231729 First 3 polynomials:  1 + x, 1 + x + x^2 + x^3, 2 + 4*x + 5*x^2 + 3*x^3 + x^4 + x^5.
%t A231729 t[n_] := t[n] = Table[(1 + x^2)/(1 + x), {k, 0, n}];
%t A231729 b = Table[Factor[Convergents[t[n]]], {n, 0, 10}];
%t A231729 p[x_, n_] := p[x, n] = Last[Expand[Denominator[b]]][[n]];
%t A231729 u = Table[p[x, n], {n, 1, 10}]
%t A231729 v = CoefficientList[u, x]; Flatten[v]
%Y A231729 Cf. A230000, A000045, A231728.
%K A231729 nonn,tabf
%O A231729 1,7
%A A231729 _Clark Kimberling_, Nov 13 2013