A211234 Triangle read by rows: T(n,k) is the k-th generalized Eulerian number of order n and degree 4, n >= 1.
1, 2, 3, 4, 1, 4, 10, 20, 10, 4, 1, 1, 7, 27, 77, 57, 0, -57, -77, -27, -7, -1, 1, 12, 69, 272, 221, -272, -1084, -1688, -1084, -272, 221, 272, 69, 12, 1, 1, 21, 176, 936, 625, -3288, -11868, -21023, -16223, 0, 16223, 21023, 11868, 3288, -625, -936, -176, -21, -1
Offset: 1
Examples
Triangle begins: 1, 2, 3, 4; 1, 4, 10, 20, 10, 4, 1; 1, 7, 27, 77, 57, 0, -57, -77, -27, -7, -1; ...
Links
- Andrew Howroyd, Table of n, a(n) for n = 1..1276 (rows 1..25)
- D. H. Lehmer, Generalized Eulerian numbers, J. Combin. Theory Ser.A 32 (1982), no. 2, 195-215. MR0654621 (83k:10026).
Crossrefs
Programs
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PARI
T(n,r=4)={my(R=vector(n)); R[1]=[1..r]; for(n=2, n, my(u=R[n-1]); R[n]=vector(r*n-1, k, sum(j=0, r, (k - j*n)*if(k>j && k-j<=#u, u[k-j], 0)))); R} { my(A=T(5)); for(n=1, #A, print(A[n])) } \\ Andrew Howroyd, May 18 2020
Formula
A047683(n) = Sum_{k>=1} T(2*n, k). - Andrew Howroyd, May 18 2020
Extensions
More terms from Franck Maminirina Ramaharo, Nov 30 2018
a(20) corrected by Andrew Howroyd, May 18 2020
Comments