Triangle read by rows: T(n,k) = one-half number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1. T(1,0) = 1 by convention.

A086856

Triangle read by rows: T(n,k) = one-half number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1. T(1,0) = 1 by convention.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =0a(4) =2a(5) =1a(6) =1a(7) =5a(8) =5a(9) =1a(10) =7a(11) =20a(12) =24a(13) =8a(14) =1a(15) =45a(16) =115a(17) =128a(18) =60a(19) =11a(20) =1a(21) =323a(22) =790a(23) =835a(24) =444a(25) =113a(26) =14a(27) =1a(28) =2621a(29) =6217

External references