cp's OEIS Frontend

A221531 Triangle read by rows: T(n,k) = A000005(n-k+1)*A000041(k-1), n>=1, k>=1.

%I A221531 #14 Feb 21 2013 15:54:21
%S A221531 1,2,1,2,2,2,3,2,4,3,2,3,4,6,5,4,2,6,6,10,7,2,4,4,9,10,14,11,4,2,8,6,
%T A221531 15,14,22,15,3,4,4,12,10,21,22,30,22,4,3,8,6,20,14,33,30,44,30,2,4,6,
%U A221531 12,10,28,22,45,44,60,42,6,2,8,9,20,14,44,30,66,60,84,56
%N A221531 Triangle read by rows: T(n,k) = A000005(n-k+1)*A000041(k-1), n>=1, k>=1.
%F A221531 T(n,k) = d(n-k+1)*p(k-1), n>=1, k>=1.
%e A221531 For n = 6:
%e A221531 -------------------------
%e A221531 k   A000041        T(6,k)
%e A221531 1      1  *  4   =    4
%e A221531 2      1  *  2   =    2
%e A221531 3      2  *  3   =    6
%e A221531 4      3  *  2   =    6
%e A221531 5      5  *  2   =   10
%e A221531 6      7  *  1   =    7
%e A221531 .         A000005
%e A221531 -------------------------
%e A221531 So row 6 is [4, 2, 6, 6, 10, 7]. Note that the sum of row 6 is 4+2+6+6+10+7 = 35 equals A006128(6).
%e A221531 .
%e A221531 Triangle begins:
%e A221531 1;
%e A221531 2,  1;
%e A221531 2,  2,  2;
%e A221531 3,  2,  4,  3;
%e A221531 2,  3,  4,  6, 5;
%e A221531 4,  2,  6,  6, 10, 7;
%e A221531 2,  4,  4,  9, 10, 14, 11;
%e A221531 4,  2,  8,  6, 15, 14, 22, 15;
%e A221531 3,  4,  4, 12, 10, 21, 22, 30, 22;
%e A221531 4,  3,  8,  6, 20, 14, 33, 30, 44, 30;
%e A221531 2,  4,  6, 12, 10, 28, 22, 45, 44, 60, 42;
%e A221531 6,  2,  8,  9, 20, 14, 44, 30, 66, 60, 84, 56;
%e A221531 ...
%Y A221531 Mirror of A221530. Columns 1-3: A000005, A000005, A062011. Leading diagonals 1-2: A000041, A139582. Row sums give A006128.
%Y A221531 Cf. A140207, A182703.
%K A221531 nonn,tabl
%O A221531 1,2
%A A221531 _Omar E. Pol_, Jan 19 2013