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 A317644 #21 Sep 23 2018 23:02:49 %S A317644 2,3,3,5,9,5,7,45,45,7,11,315,2025,315,11,13,3465,637875,637875,3465, %T A317644 13,17,45045,2210236875,406884515625,2210236875,45045,17,19,765765, %U A317644 99560120034375,899311160300888671875,899311160300888671875,99560120034375,765765,19,23,14549535,76239655318123171875,89535527067809533413858673095703125,808760563041730681160065242862701416015625,89535527067809533413858673095703125,76239655318123171875,14549535,23 %N A317644 Triangle read by rows: multiplicative version of Pascal's triangle except n-th row begins and ends with (n+1)-st prime. %F A317644 From _Rémy Sigrist_, Sep 02 2018: (Start) %F A317644 A007949(T(n+1, k+1)) = A028326(n, k) for any n >= 0 and k = 0..n. %F A317644 A112765(T(n+1, k+1)) = A007318(n, k) for any n > 0 and k = 0..n. %F A317644 (End) %e A317644 Triangle begins: %e A317644 2; %e A317644 3, 3; %e A317644 5, 9, 5; %e A317644 7, 45, 45, 7; %e A317644 11, 315, 2025, 315, 11; %e A317644 13, 3465, 637875, 637875, 3465, 13; %e A317644 ... %e A317644 Formatted as a symmetric triangle: %e A317644 . %e A317644 2 %e A317644 . %e A317644 3 3 %e A317644 . %e A317644 5 9 5 %e A317644 . %e A317644 7 45 45 7 %e A317644 . %e A317644 11 315 2025 315 11 %e A317644 . %e A317644 13 3465 637875 637875 3465 13 %e A317644 ... %t A317644 t = {{2}}; %t A317644 Table[AppendTo[ %t A317644 t, {Prime[i], %t A317644 Table[ %t A317644 t[[i - 1]][[j]]*t[[i - 1]][[j + 1]], {j, %t A317644 1, (t[[i - 1]] // Length) - 1}], Prime[i]} // Flatten], {i, 2, 10}] // %t A317644 Last // Flatten %t A317644 t={}; Do[r={}; Do[If[k==0||k==n, m=Prime[n + 1], m=t[[n, k]]t[[n, k + 1]]]; r=AppendTo[r, m], {k, 0, n}]; AppendTo[t, r], {n, 0, 10}]; t (* _Vincenzo Librandi_, Sep 03 2018 *) %Y A317644 Cf. A000040, A007318, A007949, A028326, A051599, A080046, A112765. %K A317644 nonn,tabl %O A317644 0,1 %A A317644 _Philipp O. Tsvetkov_, Aug 02 2018