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 A104793 #15 Jan 07 2025 16:52:03 %S A104793 1,5,1,13,5,1,28,13,5,1,54,28,13,5,1,98,54,28,13,5,1,171,98,54,28,13, %T A104793 5,1,291,171,98,54,28,13,5,1,487,291,171,98,54,28,13,5,1,806,487,291, %U A104793 171,98,54,28,13,5,1,1324,806,487,291,171,98,54,28,13,5,1 %N A104793 Triangle T(n,k) = A023537(n-k), n >= 1, 0 <= k < n, read by rows. %C A104793 Repeatedly writing the sequence A023537 backwards. %H A104793 G. C. Greubel, <a href="/A104793/b104793.txt">Rows n = 1..100 of triangle, flattened</a> %F A104793 From _Ralf Stephan_, Apr 05 2009: (Start) %F A104793 T(n,k) = Lucas(n-k+4) - (3*n - 3*k + 7). %F A104793 T(n,k) = A023537(A004736(n, k+1)). (End) %e A104793 First few rows of the triangle are: %e A104793 1; %e A104793 5, 1; %e A104793 13, 5, 1; %e A104793 28, 13, 5, 1; %e A104793 54, 28, 13, 5, 1; %e A104793 98, 54, 28, 13, 5, 1; ... %t A104793 Table[LucasL[n-k+4] -3*n+3*k-7, {n,1,12}, {k,0,n-1}]//Flatten (* _G. C. Greubel_, Jun 01 2019 *) %o A104793 (PARI) {T(n,k) = fibonacci(n-k+5) + fibonacci(n-k+3) -3*n +3*k - 7}; \\ _G. C. Greubel_, Jun 01 2019 %o A104793 (Magma) [[Lucas(n-k+4) -(3*n-3*k+7): k in [0..n-1]]: n in [1..12]]; // _G. C. Greubel_, Jun 01 2019 %o A104793 (Sage) [[lucas_number2(n-k+4, 1, -1) -3*n+3*k-7 for k in (0..n-1)] for n in (1..12)] # _G. C. Greubel_, Jun 01 2019 %o A104793 (GAP) Flat(List([1..12], n-> List([0..n-1], k-> Lucas(1, -1, n-k+4)[2] -3*n+3*k-7 ))); # _G. C. Greubel_, Jun 01 2019 %Y A104793 Row sums are in A027963. %Y A104793 Cf. A104765. %K A104793 nonn,tabl %O A104793 1,2 %A A104793 _Gary W. Adamson_, Mar 26 2005 %E A104793 Edited by _Ralf Stephan_, Apr 05 2009