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 A171730 #20 Jan 13 2025 08:22:48
%S A171730 1,2,1,3,2,1,5,4,3,2,8,7,6,5,3,13,12,11,10,8,5,21,20,19,18,16,13,8,34,
%T A171730 33,32,31,29,26,21,13,55,54,53,52,50,47,42,34,21,89,88,87,86,84,81,76,
%U A171730 68,55,34,144,143,142,141,139,136,131,123,110,89,55,233,232,231,230,228,225,220,212,199,178,144,89
%N A171730 Triangle of differences of Fibonacci numbers, rows descending.
%C A171730 The numbers missing from this triangle form A050939.
%C A171730 Reversing the rows gives A171729.
%H A171730 Michael De Vlieger, <a href="/A171730/b171730.txt">Table of n, a(n) for n = 1..11325</a> (rows n = 1..150, flattened)
%F A171730 Counting the top row as the first row, the n-th row is
%F A171730 F(n+1)-F(0), F(n+1)-F(2), ..., F(n+1)-F(n-1), F(n+1)-F(n).
%e A171730 First rows:
%e A171730 1
%e A171730 2 1
%e A171730 3 2 1
%e A171730 5 4 3 2
%e A171730 8 7 6 5 3
%e A171730 13 12 11 10 8 5
%e A171730 ...
%p A171730 F:= combinat[fibonacci]:
%p A171730 T:= (n,k)-> F(n+1)-`if`(k=1, 0, F(k)):
%p A171730 seq(seq(T(n,k), k=1..n), n=1..12); # _Alois P. Heinz_, Feb 06 2023
%t A171730 Table[Fibonacci[n + 1] - If[k > 1, Fibonacci[k], 0], {n, 12}, {k, n}] // Flatten (* _Michael De Vlieger_, Feb 06 2023 *)
%o A171730 (PARI) row(n) = vector(n, k, fibonacci(n+1) - if (k>1, fibonacci(k), 0)); \\ _Michel Marcus_, Feb 06 2023
%Y A171730 Cf. A000045, A050939, A143061, A171729.
%K A171730 nonn,tabl
%O A171730 1,2
%A A171730 _Clark Kimberling_, Dec 16 2009