A257614 Triangle read by rows: T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 5*n + 2.
1, 2, 2, 4, 28, 4, 8, 244, 244, 8, 16, 1844, 5856, 1844, 16, 32, 13260, 101620, 101620, 13260, 32, 64, 93684, 1511160, 3455080, 1511160, 93684, 64, 128, 657836, 20663388, 91981880, 91981880, 20663388, 657836, 128, 256, 4609588, 269011408, 2121603436, 4047202720, 2121603436, 269011408, 4609588, 256
Offset: 0
Examples
Array t(n,k) begins as: 1, 2, 4, 8, 16, ... A000079; 2, 28, 244, 1844, 13260, ...; 4, 244, 5856, 101620, 1511160, ...; 8, 1844, 101620, 3455080, 91981880, ...; 16, 13260, 1511160, 91981880, 4047202720, ...; 32, 93684, 20663388, 2121603436, 146321752612, ...; 64, 657836, 269011408, 44675623468, 4648698508440, ...; Triangle T(n,k) begins as: 1; 2, 2; 4, 28, 4; 8, 244, 244, 8; 16, 1844, 5856, 1844, 16; 32, 13260, 101620, 101620, 13260, 32; 64, 93684, 1511160, 3455080, 1511160, 93684, 64; 128, 657836, 20663388, 91981880, 91981880, 20663388, 657836, 128;
Links
- G. C. Greubel, Rows n = 0..50 of the triangle, flattened
Crossrefs
Programs
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Mathematica
t[n_, k_, p_, q_]:= t[n, k, p, q] = If[n<0 || k<0, 0, If[n==0 && k==0, 1, (p*k+q)*t[n-1,k,p,q] + (p*n+q)*t[n,k-1,p,q]]]; T[n_, k_, p_, q_]= t[n-k, k, p, q]; Table[T[n,k,5,2], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 01 2022 *)
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Sage
@CachedFunction def t(n,k,p,q): if (n<0 or k<0): return 0 elif (n==0 and k==0): return 1 else: return (p*k+q)*t(n-1,k,p,q) + (p*n+q)*t(n,k-1,p,q) def A257614(n,k): return t(n-k,k,5,2) flatten([[A257614(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 01 2022
Formula
T(n, k) = t(n-k, k), where t(0,0) = 1, t(n,m) = 0 if n < 0 or m < 0, else t(n,m) = f(m)*t(n-1,m) + f(n)*t(n,m-1), and f(n) = 5*n + 2.
Sum_{k=0..n} T(n, k) = A008546(n).
From G. C. Greubel, Mar 01 2022: (Start)
t(k, n) = t(n, k).
T(n, n-k) = T(n, k).
t(0, n) = T(n, 0) = A000079(n). (End)