A307318
a(n) = Sum_{i=0..n} Sum_{j=0..n} Sum_{k=0..n} (-1)^(i+j+k) * (i+j+k)!/(i!*j!*k!).
Original entry on oeis.org
1, -2, 37, -692, 14371, -315002, 7156969, -166785320, 3960790687, -95442311582, 2326713829837, -57260397539204, 1420295354815351, -35463581316556850, 890530353765972817, -22472131364683145552, 569507678494598796631, -14487492070374441746150
Offset: 0
-
Table[Sum[(-1)^(i + j + k) * (i + j + k)!/(i!*j!*k!), {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Apr 02 2019 *)
-
{a(n) = sum(i=0, n, sum(j=0, n, sum(k=0, n, (-1)^(i+j+k)*(i+j+k)!/(i!*j!*k!))))}
-
{a(n) = sum(i=0, 3*n, (-1)^i*i!*polcoef(sum(j=0, n, x^j/j!)^3, i))} \\ Seiichi Manyama, May 20 2019
A307324
a(n) = Sum_{i=0..n} Sum_{j=0..n} Sum_{k=0..n} Sum_{l=0..n} (-1)^(i+j+k+l) * (i+j+k+l)!/(i!*j!*k!*l!).
Original entry on oeis.org
1, 9, 997, 148041, 25413205, 4744544613, 935728207597, 191813392024137, 40462946725744501, 8726529512888314245, 1915408781755211655133, 426478330303800465141669, 96092667172064808771832957, 21869171662479233922632691261
Offset: 0
-
Table[Sum[(-1)^(i + j + k + l) * (i + j + k + l)! / (i!*j!*k!*l!), {i, 0, n}, {j, 0, n}, {k, 0, n}, {l, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Apr 02 2019 *)
Table[Sum[((-1)^(j + k + l) * 2^(-1 - j - k - l) * ((j + k + l)! * (1 + n)! + (-1)^n * 2^(1 + j + k + l) * (1 + j + k + l + n)! Hypergeometric2F1[1, 2 + j + k + l + n, 2 + n, -1]))/(j! k! l! (1 + n)!), {j, 0, n}, {k, 0, n}, {l, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Apr 03 2019 *)
-
{a(n) = sum(i=0, n, sum(j=0, n, sum(k=0, n, sum(l=0, n, (-1)^(i+j+k+l)*(i+j+k+l)!/(i!*j!*k!*l!)))))}
-
{a(n) = sum(i=0, 4*n, (-1)^i*i!*polcoef(sum(j=0, n, x^j/j!)^4, i))} \\ Seiichi Manyama, May 20 2019
A307349
a(n) = Sum_{i=1..n} Sum_{j=1..n} (-1)^(i+j) * (i+j)!/(2!*i!*j!).
Original entry on oeis.org
0, 1, 1, 5, 15, 56, 203, 757, 2839, 10736, 40821, 155948, 598065, 2301118, 8878591, 34340085, 133100055, 516851528, 2010358061, 7831136920, 30546063745, 119291436738, 466379022561, 1825168170620, 7149316835465, 28027993191706, 109965636641173
Offset: 0
-
Table[Sum[Sum[(-1)^(i + j)*(i + j)!/(2*i!*j!), {i, 1, n}], {j, 1, n}], {n, 0, 30}] (* Vaclav Kotesovec, Apr 03 2019 *)
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{a(n) = sum(i=1, n, sum(j=1, n, (-1)^(i+j)*(i+j)!/(2*i!*j!)))}
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{a(n) = sum(i=2, 2*n, (-1)^i*i!*polcoef(sum(j=1, n, x^j/j!)^2, i))/2} \\ Seiichi Manyama, May 20 2019
A307354
a(n) = Sum_{0<=i<=j<=n} (-1)^(i+j) * (i+j)!/(i!*j!).
Original entry on oeis.org
1, 2, 6, 19, 65, 231, 841, 3110, 11628, 43834, 166298, 634140, 2428336, 9331688, 35967462, 138987715, 538287881, 2088842463, 8119916647, 31613327405, 123251518641, 481125828853, 1880262896537, 7355767408395, 28803717914791, 112887697489907, 442784607413427
Offset: 0
-
Table[Sum[Sum[(-1)^(i + j)*(i + j)!/(i!*j!), {i, 0, j}], {j, 0, n}], {n, 0, 25}] (* Vaclav Kotesovec, Apr 04 2019 *)
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a(n) = sum(i=0, n, sum(j=i, n, (-1)^(i+j)*(i+j)!/(i!*j!)));
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a(n) = sum(k=0, n\3, (-1)^k*binomial(2*n-3*k, n)); \\ Seiichi Manyama, Jan 29 2023
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my(N=30, x='x+O('x^N)); Vec(1/(sqrt(1-4*x)*(1+x^3*(2/(1+sqrt(1-4*x)))^3))) \\ Seiichi Manyama, Jan 29 2023
A371798
a(n) = Sum_{k=0..floor(n/2)} (-1)^k * binomial(2*n-2*k-1,n-2*k).
Original entry on oeis.org
1, 1, 2, 7, 26, 96, 356, 1331, 5014, 19006, 72412, 277058, 1063856, 4097510, 15823432, 61245987, 237536326, 922906150, 3591500972, 13996328322, 54614894396, 213360770840, 834409399672, 3266370155262, 12797894251276, 50184309630196, 196936674150296
Offset: 0
- Harvey P. Dale, Table of n, a(n) for n = 0..1000
- Sergi Elizalde, Nadia Lafrenière, Joel Brewster Lewis, Erin McNicholas, Jessica Striker, and Amanda Welch, Enumeration of interval-closed sets via Motzkin paths and quarter-plane walks, arXiv:2412.16368 [math.CO], 2024. See p. 13.
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Table[Sum[(-1)^k Binomial[2n-2k-1,n-2k],{k,0,Floor[n/2]}],{n,0,30}] (* Harvey P. Dale, Oct 31 2024 *)
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a(n) = sum(k=0, n\2, (-1)^k*binomial(2*n-2*k-1, n-2*k));
A306409
a(n) = -Sum_{0<=i
Original entry on oeis.org
0, 1, 3, 10, 34, 120, 434, 1597, 5949, 22363, 84655, 322245, 1232205, 4729453, 18210279, 70307546, 272087770, 1055139408, 4099200524, 15951053566, 62159391150, 242542955378, 947504851414, 3705431067156, 14505084243860, 56831711106496, 222853334131080
Offset: 0
n | a(n) | A307354 | A006134 | A120305
--+------+---------+---------+---------
0 | 0 | 1 | 1 | 1
1 | 1 | 2 | 3 | 1
2 | 3 | 6 | 9 | 3
3 | 10 | 19 | 29 | 9
4 | 34 | 65 | 99 | 31
5 | 120 | 231 | 351 | 111
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Table[-Sum[Sum[(-1)^(i+j) * (i+j)!/(i!*j!), {i, 0, j-1}], {j, 0, n}], {n, 0, 25}] (* Vaclav Kotesovec, Apr 05 2019 *)
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a(n) = -sum(i=0, n, sum(j=i+1, n, (-1)^(i+j)*(i+j)!/(i!*j!)));
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my(N=30, x='x+O('x^N)); concat(0, Vec((1-sqrt(1-4*x))/(sqrt(1-4*x)*(1-x)*(3-sqrt(1-4*x))))) \\ Seiichi Manyama, Jan 30 2023
A308322
A(n,k) = Sum_{i_1=0..n} Sum_{i_2=0..n} ... Sum_{i_k=0..n} (-1)^(i_1 + i_2 + ... + i_k) * multinomial(i_1 + i_2 + ... + i_k; i_1, i_2, ..., i_k), square array A(n,k) read by antidiagonals, for n >= 0, k >= 0.
Original entry on oeis.org
1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, -2, 3, 0, 1, 1, 9, 37, 9, 1, 1, 1, -44, 997, -692, 31, 0, 1, 1, 265, 44121, 148041, 14371, 111, 1, 1, 1, -1854, 2882071, -66211704, 25413205, -315002, 407, 0, 1, 1, 14833, 260415373, 53414037505, 120965241901, 4744544613, 7156969, 1513, 1, 1
Offset: 0
For (n,k) = (3,2), (Sum_{i=0..3} x^i/i!)^2 = (1 + x + x^2/2 + x^3/6)^2 = 1 + (-2)*(-x) + 4*(-x)^2/2 + (-8)*(-x)^3/6 + 14*(-x)^4/24 + (-20)*(-x)^5/120 + 20*(-x)^6/720. So A(3,2) = 1 - 2 + 4 - 8 + 14 - 20 + 20 = 9.
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 0, 1, -2, 9, -44, ...
1, 1, 3, 37, 997, 44121, ...
1, 0, 9, -692, 148041, -66211704, ...
1, 1, 31, 14371, 25413205, 120965241901, ...
1, 0, 111, -315002, 4744544613, -247578134832564, ...
1, 1, 407, 7156969, 935728207597, 545591130328772081, ...
A371818
a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2*n-2*k,n-3*k).
Original entry on oeis.org
1, 2, 6, 19, 64, 224, 805, 2947, 10934, 40975, 154738, 587910, 2244681, 8605061, 33099767, 127687258, 493796454, 1913755319, 7431027611, 28902878561, 112585961052, 439148770623, 1715009647444, 6705019714554, 26240361155821, 102787164654287, 402972015656065
Offset: 0
A371819
a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2*n-k+1,n-3*k).
Original entry on oeis.org
1, 3, 10, 34, 118, 417, 1497, 5447, 20047, 74493, 279054, 1052467, 3992204, 15216662, 58239175, 223688159, 861769598, 3328779906, 12887832493, 49998248601, 194315972151, 756406944446, 2948649839743, 11509316352548, 44976030493706, 175942932935325
Offset: 0
A371820
a(n) = Sum_{k=0..floor(n/3)} (-1)^k * binomial(2*n+2,n-3*k).
Original entry on oeis.org
1, 4, 15, 55, 200, 726, 2640, 9636, 35343, 130339, 483395, 1802901, 6760781, 25482643, 96506229, 367077447, 1401772536, 5372120718, 20653929804, 79634421312, 307826528346, 1192608522258, 4629875048634, 18006340509702, 70142823370656, 273633773330844
Offset: 0
Showing 1-10 of 13 results.