A176120
Triangle read by rows: Sum_{j=0..k} binomial(n, j)*binomial(k, j)*j!.
Original entry on oeis.org
1, 1, 2, 1, 3, 7, 1, 4, 13, 34, 1, 5, 21, 73, 209, 1, 6, 31, 136, 501, 1546, 1, 7, 43, 229, 1045, 4051, 13327, 1, 8, 57, 358, 1961, 9276, 37633, 130922, 1, 9, 73, 529, 3393, 19081, 93289, 394353, 1441729, 1, 10, 91, 748, 5509, 36046, 207775, 1047376, 4596553, 17572114
Offset: 0
Triangle begins
1;
1, 2;
1, 3, 7;
1, 4, 13, 34;
1, 5, 21, 73, 209;
1, 6, 31, 136, 501, 1546;
1, 7, 43, 229, 1045, 4051, 13327;
1, 8, 57, 358, 1961, 9276, 37633, 130922;
1, 9, 73, 529, 3393, 19081, 93289, 394353, 1441729;
1, 10, 91, 748, 5509, 36046, 207775, 1047376, 4596553, 17572114;
1, 11, 111, 1021, 8501, 63591, 424051, 2501801, 12975561, 58941091, 234662231;
- O. Ganyushkin and V. Mazorchuk, Classical Finite Transformation Semigroups, Springer, 2009, page 46.
-
A176120:=func< n,k| (&+[Factorial(j)*Binomial(n,j)*Binomial(k,j): j in [0..k]]) >;
[A176120(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Aug 11 2022
-
A176120 := proc(i,j)
add(binomial(i,k)*binomial(j,k)*k!,k=0..j) ;
end proc: # R. J. Mathar, Jul 28 2016
-
T[n_, m_]:= T[n,m]= Sum[Binomial[n, k]*Binomial[m, k]*k!, {k, 0, m}];
Table[T[n, m], {n,0,12}, {m,0,n}]//Flatten
-
def A176120(n,k): return sum(factorial(j)*binomial(n,j)*binomial(k,j) for j in (0..k))
flatten([[A176120(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Aug 11 2022
A293985
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(x/(1-x))/(1-x)^k.
Original entry on oeis.org
1, 1, 1, 1, 2, 3, 1, 3, 7, 13, 1, 4, 13, 34, 73, 1, 5, 21, 73, 209, 501, 1, 6, 31, 136, 501, 1546, 4051, 1, 7, 43, 229, 1045, 4051, 13327, 37633, 1, 8, 57, 358, 1961, 9276, 37633, 130922, 394353, 1, 9, 73, 529, 3393, 19081, 93289, 394353, 1441729, 4596553
Offset: 0
Square array begins:
1, 1, 1, 1, 1, ... A000012;
1, 2, 3, 4, 5, ... A000027;
3, 7, 13, 21, 31, ... A002061;
13, 34, 73, 136, 229, ... A135859;
73, 209, 501, 1045, 1961, ...
501, 1546, 4051, 9276, 19081, ...
Antidiagonal rows begin as:
1;
1, 1;
1, 2, 3;
1, 3, 7, 13;
1, 4, 13, 34, 73;
1, 5, 21, 73, 209, 501; - _G. C. Greubel_, Mar 09 2021
-
function t(n,k)
if n eq 0 then return 1;
else return Factorial(n-1)*(&+[(j+k)*t(n-j,k)/Factorial(n-j): j in [1..n]]);
end if; return t;
end function;
[t(k,n-k): k in [0..n], n in [0..12]]; // G. C. Greubel, Mar 09 2021
-
t[n_, k_]:= t[n, k]= If[n==0, 1, (n-1)!*Sum[(j+k)*t[n-j,k]/(n-j)!, {j,n}]];
T[n_,k_]:= t[k,n-k]; Table[T[n,k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Mar 09 2021 *)
-
@CachedFunction
def t(n,k): return 1 if n==0 else factorial(n-1)*sum( (j+k)*t(n-j,k)/factorial(n-j) for j in (1..n) )
def T(n,k): return t(k,n-k)
flatten([[T(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, Mar 09 2021
A093190
Array t read by antidiagonals: number of {112,212}-avoiding words.
Original entry on oeis.org
1, 1, 2, 1, 4, 3, 1, 6, 9, 4, 1, 8, 21, 16, 5, 1, 10, 39, 52, 25, 6, 1, 12, 63, 136, 105, 36, 7, 1, 14, 93, 292, 365, 186, 49, 8, 1, 16, 129, 544, 1045, 816, 301, 64, 9, 1, 18, 171, 916, 2505, 3006, 1603, 456, 81, 10, 1, 20, 219, 1432, 5225, 9276, 7315, 2864, 657, 100, 11
Offset: 1
Square array begins as:
1 1 1 1 1 1 ... 1*A000012;
2 4 6 8 10 12 ... 2*A000027;
3 9 21 39 63 93 ... 3*A002061;
4 16 52 136 292 544 ... 4*A135859;
5 25 105 365 1045 2505 ... ;
Antidiagonal rows begins as:
1;
1, 2;
1, 4, 3;
1, 6, 9, 4;
1, 8, 21, 16, 5;
1, 10, 39, 52, 25, 6;
1, 12, 63, 136, 105, 36, 7;
Antidiagonal sums are in
A084261 - 1.
-
[(&+[Factorial(j)*Binomial(k,j)*Binomial(n-k,j-1): j in [0..n-k+1]]): k in [1..n], n in [1..12]]; // G. C. Greubel, Mar 09 2021
-
T[n_, k_]:= Sum[j!*Binomial[k, j]*Binomial[n-k, j-1], {j,0,n-k+1}];
Table[T[n, k], {n,12}, {k,n}]//Flatten (* G. C. Greubel, Mar 09 2021 *)
-
t(n,k)=sum(j=0,k,j!*binomial(k,j)*binomial(n-1,j-1))
-
flatten([[ sum(factorial(j)*binomial(k,j)*binomial(n-k,j-1) for j in (0..n-k+1)) for k in (1..n)] for n in (1..12)]) # G. C. Greubel, Mar 09 2021
Original entry on oeis.org
1, 3, 1, 7, 5, 1, 13, 13, 7, 1, 21, 21, 21, 9, 1, 31, 31, 31, 31, 11, 1, 43, 43, 43, 43, 43, 13, 1, 57, 57, 57, 57, 57, 57, 15, 1, 73, 73, 73, 73, 73, 73, 73, 17, 1, 91, 91, 91, 91, 91, 91, 91, 91, 19, 1
Offset: 1
First few rows of the triangle:
1;
3, 1;
7, 5, 1;
13, 13, 7, 1;
21, 21, 21, 9, 1;
31, 31, 31, 31, 11, 1;
43, 43, 43, 43, 43, 13, 1;
...
Showing 1-4 of 4 results.
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