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 A247327 #12 Feb 27 2015 23:32:55 %S A247327 1,4,12,9,27,45,16,48,80,112,25,75,125,175,225,36,108,180,252,324,396, %T A247327 49,147,245,343,441,539,637,64,192,320,448,576,704,832,960,81,243,405, %U A247327 567,729,891,1053,1215,1377,100,300,500,700,900,1100,1300,1500,1700,1900,121,363 %N A247327 Triangle read by rows: T(n,k) = sum of k-th row of n X n square filled with odd numbers 1 through 2*n^2-1 reading across rows left-to-right. %C A247327 See illustration in links. Column c(k) = (2*k - 1)*n^2. Diagonal d(m) = (2*n - 2*m + 1)*n^2. %H A247327 Kival Ngaokrajang, <a href="/A247327/a247327.pdf">Illustration of initial terms</a> %e A247327 Triangle begins: %e A247327 1 %e A247327 4 12 %e A247327 9 27 45 %e A247327 16 48 80 112 %e A247327 25 75 125 175 225 %e A247327 36 108 180 252 324 396 %e A247327 49 147 245 343 441 539 637 %o A247327 (Small Basic) %o A247327 For n=1 To 20 %o A247327 For k=1 To n*n+(n-1)*(n-1) Step 2*n %o A247327 c=0 %o A247327 For i=1 To n %o A247327 If i=1 Then %o A247327 a=k %o A247327 Else %o A247327 a=a+2 %o A247327 EndIf %o A247327 c=c+a %o A247327 EndFor %o A247327 TextWindow.Write(c+", ") %o A247327 EndFor %o A247327 EndFor %o A247327 (PARI) trg(nn) = {for (n=1, nn, mm = matrix(n, n, i, j, (2*j-1) + (2*n)*(i-1)); for (i=1, n, print1(sum(j=1, n, mm[i, j]), ", ");); print(););} \\ _Michel Marcus_, Sep 15 2014 %Y A247327 Column: c(1) = A000290, c(2) = A033428, c(3) = A033429. %Y A247327 Diagonal: d(1) = A015237, d(2) = A015238, d(3) = A015240. %Y A247327 Rows sum: A000538. %Y A247327 Cf. A241016. %K A247327 nonn,tabl %O A247327 1,2 %A A247327 _Kival Ngaokrajang_, Sep 13 2014