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 A141429 #14 Mar 31 2021 01:29:19 %S A141429 2,4,3,6,6,4,8,9,8,5,10,12,12,10,6,12,15,16,15,12,7,14,18,20,20,18,14, %T A141429 8,16,21,24,25,24,21,16,9,18,24,28,30,30,28,24,18,10,20,27,32,35,36, %U A141429 35,32,27,20,11,22,30,36,40,42,42,40,36,30,22,12,24,33,40,45,48,49,48,45,40,33,24,13 %N A141429 Triangle T(n, k) = (k+1)*(n-k+1), read by rows. %H A141429 G. C. Greubel, <a href="/A141429/b141429.txt">Rows n = 1..50 of the triangle, flattened</a> %F A141429 T(n, k) = (k+1)*(n-k+1). %F A141429 T(n, k) = A158823(n+2, k+2). %F A141429 Sum_{k=1..n} T(n, k) = A005581(n+1). %e A141429 Triangle begins as: %e A141429 2; %e A141429 4, 3; %e A141429 6, 6, 4; %e A141429 8, 9, 8, 5; %e A141429 10, 12, 12, 10, 6; %e A141429 12, 15, 16, 15, 12, 7; %e A141429 14, 18, 20, 20, 18, 14, 8; %e A141429 16, 21, 24, 25, 24, 21, 16, 9; %e A141429 18, 24, 28, 30, 30, 28, 24, 18, 10; %e A141429 20, 27, 32, 35, 36, 35, 32, 27, 20, 11; %p A141429 A141429 := proc(n,k) %p A141429 (k+1)*(n-k+1) ; %p A141429 end proc: %p A141429 seq(seq(A141429(n,m),m=1..n),n=1..14) ; # _R. J. Mathar_, Nov 10 2011 %t A141429 Table[(k+1)*(n-k+1), {n,15}, {k,n}]//Flatten %o A141429 (Magma) [(k+1)*(n-k+1): k in [1..n], n in [1..15]]; // _G. C. Greubel_, Mar 30 2021 %o A141429 (Sage) flatten([[(k+1)*(n-k+1) for k in (1..n)] for n in (1..15)]) # _G. C. Greubel_, Mar 30 2021 %Y A141429 Cf. A003991, A004247, A005581, A144329, A158823. %K A141429 nonn,easy,tabl %O A141429 1,1 %A A141429 _Roger L. Bagula_ and _Gary W. Adamson_, Aug 06 2008 %E A141429 Edited by _G. C. Greubel_, Mar 30 2021