Original entry on oeis.org
1, 1, 7, 31, 175, 991, 5881, 35617, 219871, 1376095, 8710537, 55644337, 358198369, 2320792657, 15120204295, 98984058271, 650725327231, 4293779332927, 28425752310361, 188739799967425, 1256510215733185
Offset: 0
A334549
Array read by antidiagonals: T(n,k) is the number of {-1,0,1} n X k matrices with all rows and columns summing to zero.
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 7, 7, 1, 1, 1, 1, 19, 31, 19, 1, 1, 1, 1, 51, 175, 175, 51, 1, 1, 1, 1, 141, 991, 2371, 991, 141, 1, 1, 1, 1, 393, 5881, 32611, 32611, 5881, 393, 1, 1, 1, 1, 1107, 35617, 481381, 1084851, 481381, 35617, 1107, 1, 1
Offset: 0
Array begins:
====================================================================
n\k | 0 1 2 3 4 5 6 7
----|---------------------------------------------------------------
0 | 1 1 1 1 1 1 1 1 ...
1 | 1 1 1 1 1 1 1 1 ...
2 | 1 1 3 7 19 51 141 393 ...
3 | 1 1 7 31 175 991 5881 35617 ...
4 | 1 1 19 175 2371 32611 481381 7343449 ...
5 | 1 1 51 991 32611 1084851 39612501 1509893001 ...
6 | 1 1 141 5881 481381 39612501 3680774301 360255871641 ...
7 | 1 1 393 35617 7343449 1509893001 360255871641 ...
...
The T(3,2) = 7 matrices are:
[0 0] [ 0 0] [ 0 0] [ 1 -1] [-1 1] [ 1 -1] [-1 1]
[0 0] [ 1 -1] [-1 1] [ 0 0] [ 0 0] [-1 1] [ 1 -1]
[0 0] [-1 1] [ 1 -1] [-1 1] [ 1 -1] [ 0 0] [ 0 0]
Columns k=0..14 are
A000012,
A000012,
A002426,
A172634,
A172642,
A172639,
A172633,
A172636,
A172638,
A172641,
A172637,
A172644,
A172640,
A172643,
A172635.
A328747
Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) is Sum_{i=0..n} (-1)^(n-i)*binomial(n,i)*Sum_{j=0..i} binomial(i,j)^k.
Original entry on oeis.org
1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 3, 1, 0, 1, 1, 7, 7, 1, 0, 1, 1, 15, 31, 19, 1, 0, 1, 1, 31, 115, 175, 51, 1, 0, 1, 1, 63, 391, 1255, 991, 141, 1, 0, 1, 1, 127, 1267, 8071, 13671, 5881, 393, 1, 0, 1, 1, 255, 3991, 49399, 161671, 160461, 35617, 1107, 1, 0
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, ...
0, 1, 3, 7, 15, 31, ...
0, 1, 7, 31, 115, 391, ...
0, 1, 19, 175, 1255, 8071, ...
0, 1, 51, 991, 13671, 161671, ...
-
T[n_, k_] := Sum[(-1)^(n-i) * Binomial[n, i] * Sum[Binomial[i, j]^k, {j, 0, i}], {i, 0, n}]; Table[T[k, n - k], {n, 0, 10}, {k, 0, n}] // Flatten (* Amiram Eldar, May 06 2021 *)
A328725
Constant term in the expansion of (1 + x + y + z + 1/x + 1/y + 1/z + x*y + y*z + z*x + 1/(x*y) + 1/(y*z) + 1/(z*x) + x*y*z + 1/(x*y*z))^n.
Original entry on oeis.org
1, 1, 15, 115, 1255, 13671, 160461, 1936425, 24071895, 305313415, 3939158905, 51521082405, 681635916325, 9105864515125, 122657982366375, 1664151758259915, 22720725637684215, 311933068664333175, 4303704125389134825, 59640225721889127525, 829774531966386480705
Offset: 0
Sum_{i=0..n} (-1)^(n-i)*binomial(n,i)*Sum_{j=0..i} binomial(i,j)^m:
A002426 (m=2),
A172634 (m=3), this sequence (m=4),
A328750 (m=5).
-
{a(n) = polcoef(polcoef(polcoef((-1+(1+x)*(1+y)*(1+z)+(1+1/x)*(1+1/y)*(1+1/z))^n, 0), 0), 0)}
-
{a(n) = sum(i=0, n, (-1)^(n-i)*binomial(n,i)*sum(j=0, i, binomial(i, j)^4))}
A262704
Triangle: Newton expansion of C(n,m)^3, read by rows.
Original entry on oeis.org
1, 0, 1, 0, 6, 1, 0, 6, 24, 1, 0, 0, 114, 60, 1, 0, 0, 180, 690, 120, 1, 0, 0, 90, 2940, 2640, 210, 1, 0, 0, 0, 5670, 21840, 7770, 336, 1, 0, 0, 0, 5040, 87570, 107520, 19236, 504, 1, 0, 0, 0, 1680, 189000, 735210, 407400, 42084, 720, 1, 0, 0, 0, 0, 224700, 2835756, 4280850, 1284360, 83880, 990, 1
Offset: 0
Triangle starts:
n\m [0] [1] [2] [3] [4] [5] [6] [7] [8]
[0] 1;
[1] 0, 1;
[2] 0, 6, 1;
[3] 0, 6, 24, 1;
[4] 0, 0, 114, 60, 1;
[5] 0, 0, 180, 690, 120, 1;
[6] 0, 0, 90, 2940, 2640, 210, 1;
[7] 0, 0, 0, 5670, 21840, 7770, 336, 1;
[8] 0, 0, 0, 5040, 87570, 107520, 19236, 504, 1;
[9] ...
Row sums are
A172634, the inverse binomial transform of the Franel numbers (
A000172).
Second diagonal (T_3(n+1,n)) is
A007531 (n+2).
-
[&+[(-1)^(n-j)*Binomial(n,j)*Binomial(j,m)^3: j in [0..n]]: m in [0..n], n in [0..10]]; // Bruno Berselli, Oct 01 2015
-
T3[n_, m_] := Sum[(-1)^(n - j) * Binomial[n, j] * Binomial[j, m]^3, {j, 0, n}]; Table[T3[n, m], {n, 0, 10}, {m, 0, n}] // Flatten (* Jean-François Alcover, Oct 01 2015 *)
-
// as a function
T_3:=(n,m)->_plus((-1)^(n-j)*binomial(n,j)*binomial(j,m)^3 $ j=0..n):
// as a matrix h x h
_P:=h->matrix([[binomial(n,m) $m=0..h]$n=0..h]):
_P_3:=h->matrix([[binomial(n,m)^3 $m=0..h]$n=0..h]):
_T_3:=h->_P(h)^-1*_P_3(h):
-
T_3(nmax) = {for(n=0, nmax, for(m=0, n, print1(sum(j=0, n, (-1)^(n-j)*binomial(n,j)*binomial(j,m)^3), ", ")); print())} \\ Colin Barker, Oct 01 2015
-
t3(n,m) = sum(j=0, n, (-1)^((n-j)%2)* binomial(n,j)*binomial(j,m)^3);
concat(vector(11, n, vector(n, k, t3(n-1,k-1)))) \\ Gheorghe Coserea, Jul 14 2016
A377065
Number of 3 X n 0..2 matrices with row sums n and column sums 3 up to permutations of rows.
Original entry on oeis.org
1, 1, 2, 6, 30, 166, 981, 5937, 36646, 229350, 1451757, 9274057, 59699729, 386798777, 2520034050, 16497343046, 108454221206, 715629888822, 4737625385061, 31456633327905, 209418369288865, 1397521222483385, 9346484009527370, 62632803958053870, 420481623373564025
Offset: 0
The a(2) = 2 matrices are:
[1 1] [2 0]
[1 1] [0 2]
[1 1] [1 1]
The a(3) = 6 matrices are:
[1 1 1] [2 1 0] [2 0 1] [1 2 0] [2 1 0] [2 0 1]
[1 1 1] [0 1 2] [0 2 0] [1 0 2] [1 0 2] [1 2 0]
[1 1 1] [1 1 1] [1 1 1] [1 1 1] [0 2 1] [0 1 2]
-
a(n)={(5+sum(i=0, n, sum(j=0, i, (-1)^(n-i)*binomial(n, i)*binomial(i, j)^3)))/6}
A377067
Number of n X 3 0..2 matrices with row sums 3 and column sums n up to permutations of rows.
Original entry on oeis.org
1, 1, 4, 6, 12, 18, 30, 42, 63, 85, 118, 154, 204, 258, 330, 408, 507, 615, 748, 892, 1066, 1254, 1476, 1716, 1995, 2295, 2640, 3010, 3430, 3880, 4386, 4926, 5529, 6171, 6882, 7638, 8470, 9352, 10318, 11340, 12453, 13629, 14904, 16248, 17700, 19228, 20872, 22600, 24453, 26397, 28476
Offset: 0
The a(2) = 4 matrices are:
[1 1 1] [2 1 0] [2 0 1] [1 2 0]
[1 1 1] [0 1 2] [0 2 0] [1 0 2]
The a(3) = 6 matrices are:
[1 1 1] [2 1 0] [2 0 1] [1 2 0] [2 1 0] [2 0 1]
[1 1 1] [0 1 2] [0 2 0] [1 0 2] [1 0 2] [1 2 0]
[1 1 1] [1 1 1] [1 1 1] [1 1 1] [0 2 1] [0 1 2]
- Andrew Howroyd, Table of n, a(n) for n = 0..1000
- Index entries for linear recurrences with constant coefficients, signature (2,1,-3,-1,1,3,-1,-2,1).
Showing 1-7 of 7 results.
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