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 A221531 Triangle read by rows: T(n,k) = A000005(n-k+1)*A000041(k-1), n>=1, k>=1. 0
 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, 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, 12, 10, 28, 22, 45, 44, 60, 42, 6, 2, 8, 9, 20, 14, 44, 30, 66, 60, 84, 56 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS FORMULA T(n,k) = d(n-k+1)*p(k-1), n>=1, k>=1. EXAMPLE For n = 6: ------------------------- k   A000041        T(6,k) 1      1  *  4   =    4 2      1  *  2   =    2 3      2  *  3   =    6 4      3  *  2   =    6 5      5  *  2   =   10 6      7  *  1   =    7 .         A000005 ------------------------- 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). . Triangle begins: 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, 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, 12, 10, 28, 22, 45, 44, 60, 42; 6,  2,  8,  9, 20, 14, 44, 30, 66, 60, 84, 56; ... CROSSREFS Mirror of A221530. Columns 1-3: A000005, A000005, A062011. Leading diagonals 1-2: A000041, A139582. Row sums give A006128. Cf. A140207, A182703. Sequence in context: A261679 A147657 A029232 * A282970 A025807 A120254 Adjacent sequences:  A221528 A221529 A221530 * A221532 A221533 A221534 KEYWORD nonn,tabl AUTHOR Omar E. Pol, Jan 19 2013 STATUS approved

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Last modified April 5 22:49 EDT 2020. Contains 333260 sequences. (Running on oeis4.)