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 A339106 #48 Jan 10 2021 11:21:36 %S A339106 1,3,1,4,3,2,7,4,6,3,6,7,8,9,5,12,6,14,12,15,7,8,12,12,21,20,21,11,15, %T A339106 8,24,18,35,28,33,15,13,15,16,36,30,49,44,45,22,18,13,30,24,60,42,77, %U A339106 60,66,30,12,18,26,45,40,84,66,105,88,90,42,28,12,36,39,75,56,132,90,154,120,126,56 %N A339106 Triangle read by rows: T(n,k) = A000203(n-k+1)*A000041(k-1), n >= 1, 1 <= k <= n. %C A339106 Conjecture 1: T(n,k) is the sum of all divisors of all (n - k + 1)'s in the n-th row of triangle A176206, assuming that A176206 has offset 1. The same for the triangle A340061. %C A339106 Conjecture 2: the sum of row n equals A066186(n), the sum of all parts of all partitions of n. %F A339106 T(n,k) = sigma(n-k+1)*p(k-1), n >= 1, 1 <= k <= n. %e A339106 Triangle begins: %e A339106 1; %e A339106 3, 1; %e A339106 4, 3, 2; %e A339106 7, 4, 6, 3; %e A339106 6, 7, 8, 9, 5; %e A339106 12, 6, 14, 12, 15, 7; %e A339106 8, 12, 12, 21, 20, 21, 11; %e A339106 15, 8, 24, 18, 35, 28, 33, 15; %e A339106 13, 15, 16, 36, 30, 49, 44, 45, 22; %e A339106 18, 13, 30, 24, 60, 42, 77, 60, 66, 30; %e A339106 12, 18, 26, 45, 40, 84, 66, 105, 88, 90, 42; %e A339106 28, 12, 36, 39, 75, 56, 132, 90, 154, 120, 126, 56; %e A339106 ... %e A339106 For n = 6 the calculation of every term of row 6 is as follows: %e A339106 ------------------------- %e A339106 k A000041 T(6,k) %e A339106 1 1 * 12 = 12 %e A339106 2 1 * 6 = 6 %e A339106 3 2 * 7 = 14 %e A339106 4 3 * 4 = 12 %e A339106 5 5 * 3 = 15 %e A339106 6 7 * 1 = 7 %e A339106 . A000203 %e A339106 ------------------------- %e A339106 The sum of row 6 is 12 + 6 + 14 + 12 + 15 + 7 = 66, equaling A066186(6). %t A339106 T[n_, k_] := DivisorSigma[1, n - k + 1] * PartitionsP[k - 1]; Table[T[n, k], {n, 1, 12}, {k, 1, n}] // Flatten (* _Amiram Eldar_, Jan 08 2021 *) %o A339106 (PARI) T(n, k) = sigma(n-k+1)*numbpart(k-1); \\ _Michel Marcus_, Jan 08 2021 %Y A339106 Mirror of A221529. %Y A339106 Row sums give A066186 (conjectured). %Y A339106 Main diagonal gives A000041. %Y A339106 Columns 1 and 2 give A000203. %Y A339106 Column 3 gives A074400. %Y A339106 Column 4 gives A272027. %Y A339106 Column 5 gives A274535. %Y A339106 Column 6 gives A319527. %Y A339106 Cf. A176206, A340061. %K A339106 nonn,tabl %O A339106 1,2 %A A339106 _Omar E. Pol_, Nov 23 2020