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 A241016 #28 Aug 23 2017 16:06:21 %S A241016 1,3,7,6,15,24,10,26,42,58,15,40,65,90,115,21,57,93,129,165,201,28,77, %T A241016 126,175,224,273,322,36,100,164,228,292,356,420,484,45,126,207,288, %U A241016 369,450,531,612,693,55,155,255,355,455,555,655,755,855,955,66,187,308,429,550 %N A241016 Triangle read by rows: T(n, k) = sum of k-th row of n X n square filled with the numbers 1 through n^2 reading across rows left-to-right. %C A241016 See illustration in links. %C A241016 The corresponding triangle with column sums is found in A251630. - _Wolfdieter Lang_, Dec 09 2014 %H A241016 G. C. Greubel, <a href="/A241016/b241016.txt">Table of n, a(n) for the first 50 rows, flattened</a> %H A241016 Kival Ngaokrajang, <a href="/A241016/a241016.pdf">Illustration of initial terms</a> %F A241016 T(n, k) = Sum_{j=1..n} (n*(k-1)+ j), for n >= k >= 1. See the _Michel Marcus_ program. - _Wolfdieter Lang_, Dec 08 2014 %F A241016 T(n, k) = binomial(n+1, 2) + n^2*(k-1). - _Wolfdieter Lang_, Dec 09 2014 %e A241016 The triangle T(n, k) begins: %e A241016 n\k 1 2 3 4 5 6 7 8 9 10 ... %e A241016 1: 1 %e A241016 2: 3 7 %e A241016 3: 6 15 24 %e A241016 4: 10 26 42 58 %e A241016 5: 15 40 65 90 115 %e A241016 6: 21 57 93 129 165 201 %e A241016 7: 28 77 126 175 224 273 322 %e A241016 8: 36 100 164 228 292 356 420 484 %e A241016 9: 45 126 207 288 369 450 531 612 693 %e A241016 10: 55 155 255 355 455 555 655 755 855 955 %e A241016 ... reformatted - _Wolfdieter Lang_, Dec 08 2014 %t A241016 Table[Sum[n*(k - 1) + j, {j,1,n}], {n,1,10}, {k,1,n}] // Flatten (* _G. C. Greubel_, Aug 23 2017 *) %o A241016 (Small Basic) %o A241016 For n=1 To 20 %o A241016 For k=1 To n*n-(n-1) Step n %o A241016 c=0 %o A241016 For i=1 To n %o A241016 If i=1 Then %o A241016 a=k %o A241016 Else %o A241016 a=a+1 %o A241016 EndIf %o A241016 c=c+a %o A241016 EndFor %o A241016 TextWindow.Write(c+", ") %o A241016 EndFor %o A241016 EndFor %o A241016 (PARI) trg(nn) = {for (n=1, nn, mm = matrix(n, n, i, j, j + n*(i-1)); for (i=1, n, print1(sum(j=1, n, mm[i, j]), ", ");); print(););} \\ _Michel Marcus_, Sep 15 2014 %Y A241016 Columns k=1..6: A000217, A005449, A005475, A022265, A022267, A022269. %Y A241016 Diagonals: A081436, A059270, ... %Y A241016 Row sums: A037270. %K A241016 nonn,easy,tabl %O A241016 1,2 %A A241016 _Kival Ngaokrajang_, Aug 08 2014 %E A241016 Edited. - _Wolfdieter Lang_, Dec 08 2014