A141674 - OEIS

%I #24 Jan 05 2024 14:58:04

%S 1,4,2,6,0,2,12,6,0,3,10,0,0,0,2,24,12,8,0,0,4,14,0,0,0,0,0,2,32,16,0,

%T 8,0,0,0,4,27,0,9,0,0,0,0,0,3,40,20,0,0,8,0,0,0,0,4,22,0,0,0,0,0,0,0,

%U 0,0,2,72,36,24,18,0,12,0,0,0,0,0,6,26,0,0,0,0,0,0,0,0,0,0,0,2,56,28,0,0,0,0,8,0,0,0,0,0,0,4

%N Triangle T(n,m) read by rows: T(n,m) = sigma_0(n) * A126988(n,m).

%C Row sums are {1, 6, 8, 21, 12, 48, 16, 60, 39, 72}.

%H G. C. Greubel, <a href="/A141674/b141674.txt">Rows n = 1..100 of triangle, flattened</a>

%F T(n,m) = sigma_0(n) * A126988(n,m).

%F T(n,m) = sigma_0(n) * if(m = 1, n, if(n mod m = 0, n/m, 0)).

%e Triangle begins

%e   { 1},

%e   { 4,  2},

%e   { 6,  0,  2},

%e   {12,  6,  0,  3},

%e   {10,  0,  0,  0,  2},

%e   {24, 12,  8,  0,  0,  4},

%e   {14,  0,  0,  0,  0,  0,  2},

%e   {32, 16,  0,  8,  0,  0,  0,  4},

%e   {27,  0,  9,  0,  0,  0,  0,  0,  3},

%e   {40, 20,  0,  0,  8,  0,  0,  0,  0,  4}

%t t[n_, m_] = DivisorSigma[0, n]*If[m == 1, n, If[Mod[n, m] == 0, n/m, 0]]; Table[Table[t[n, m], {m, 1, n}], {n, 1, 10}]; Flatten[%]

%Y Cf. A126988.

%K nonn,tabl,easy,less

%O 1,2

%A _Roger L. Bagula_ and _Gary W. Adamson_, Sep 06 2008

%E Edited by the Associate Editors of the OEIS, Jun 10 2018