%I A138765
%S A138765 2,5,3,10,24,10,17,99,145,24,26,288,1090,840,65,37,675,5185,11880,4901,
%T A138765 168,50,1368,18226,93024,129601,28560,441,65,2499,51985,491400,1669265,
%U A138765 1413720,166465,1155,82,4224,127450,1964024,13249601,29953728,15421330
%N A138765 Triangle read by rows, derived from a(n) = N*a(n-1) + a(n-2).
%C A138765 Inverse sums of second array terms by rows = 1/1, 1/4, 1/9, 1/16,...; 
               =
%C A138765 Sum__{n=1..inf}{1/a(n)} = Pi^2/6 = 1.6449340668...
%F A138765 Triangle read by rows, antidiagonals of a secondary array. The first 
               array = sequences of the form a(n) = N*a(n-1) + a(n-2). N = 1: 1, 
               1, 2, 3,... N = 2: 1, 2, 5, 12,... N = 3: 1, 3, 10, 33,... .. The 
               second array = (for N = 1,2,3,...) k(1)*k(3), k(2)*k(4), k(3)*k(5),
               ...: 2,....3,....10,.....24,.... 5,...24,...245,....840,... 10,..99,
               ..1090,..11880,... .. The triangle = antidiagonals of the secondary 
               array.
%e A138765 First few rows of the triangle are:
%e A138765 2;
%e A138765 5, 3;
%e A138765 10, 24, 10;
%e A138765 17, 99, 145, 24;
%e A138765 26, 288, 1090, 840, 65;
%e A138765 37, 675, 5185, 11880, 4901, 168;
%e A138765 50, 1368, 18226, 93024, 129601, 28560, 442;
%e A138765 ...
%Y A138765 Sequence in context: A163254 A143121 A101492 this_sequence A097753 A120860 
               A091809
%Y A138765 Adjacent sequences: A138762 A138763 A138764 this_sequence A138766 A138767 
               A138768
%K A138765 nonn,tabl
%O A138765 1,1
%A A138765 Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 30 2008