A258829
Number T(n,k) of permutations p of [n] such that the up-down signature of 0,p has nonnegative partial sums with a maximal value of k; triangle T(n,k), n>=0, 0<=k<=n, read by rows.
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 2, 2, 1, 0, 5, 11, 3, 1, 0, 16, 38, 28, 4, 1, 0, 61, 263, 130, 62, 5, 1, 0, 272, 1260, 1263, 340, 129, 6, 1, 0, 1385, 10871, 8090, 4734, 819, 261, 7, 1, 0, 7936, 66576, 88101, 33855, 16066, 1890, 522, 8, 1, 0, 50521, 694599, 724189, 495371, 127538, 52022, 4260, 1040, 9, 1
Offset: 0
p = 1432 is counted by T(4,2) because the up-down signature of 0,p = 01432 is 1,1,-1,-1 with partial sums 1,2,1,0.
q = 4321 is not counted by any T(4,k) because the up-down signature of 0,q = 04321 is 1,-1,-1,-1 with partial sums 1,0,-1,-2.
T(4,1) = 5: 2143, 3142, 3241, 4132, 4231.
T(4,2) = 11: 1324, 1423, 1432, 2134, 2314, 2413, 2431, 3124, 3412, 3421, 4123.
T(4,3) = 3: 1243, 1342, 2341.
T(4,4) = 1: 1234.
Triangle T(n,k) begins:
1;
0, 1;
0, 1, 1;
0, 2, 2, 1;
0, 5, 11, 3, 1;
0, 16, 38, 28, 4, 1;
0, 61, 263, 130, 62, 5, 1;
0, 272, 1260, 1263, 340, 129, 6, 1;
0, 1385, 10871, 8090, 4734, 819, 261, 7, 1;
Columns k=0-10 give:
A000007,
A000111 for n>0,
A259213,
A316390,
A316391,
A316392,
A316393,
A316394,
A316395,
A316396,
A316397.
-
b:= proc(u, o, c, k) option remember;
`if`(c<0 or c>k, 0, `if`(u+o=0, 1,
add(b(u-j, o-1+j, c+1, k), j=1..u)+
add(b(u+j-1, o-j, c-1, k), j=1..o)))
end:
A:= (n, k)-> b(n, 0$2, k):
T:= (n, k)-> A(n, k) -`if`(k=0, 0, A(n, k-1)):
seq(seq(T(n, k), k=0..n), n=0..12);
-
b[u_, o_, c_, k_] := b[u, o, c, k] = If[c < 0 || c > k, 0, If[u + o == 0, 1, Sum[b[u - j, o - 1 + j, c + 1, k], {j, 1, u}] + Sum[b[u + j - 1, o - j, c - 1, k], {j, 1, o}]]];
A[n_, k_] := b[n, 0, 0, k];
T[n_, k_] := A[n, k] - If[k == 0, 0, A[n, k - 1]];
Table[T[n, k], {n, 0, 12}, { k, 0, n}] // Flatten (* Jean-François Alcover, Jun 09 2018, after Alois P. Heinz *)
A263776
Triangle read by rows: T(n,k) (n>=0, 0<=k<=A002620(n-1)) is the number of permutations of [n] with k nestings.
Original entry on oeis.org
1, 1, 2, 5, 1, 14, 8, 2, 42, 45, 25, 7, 1, 132, 220, 198, 112, 44, 12, 2, 429, 1001, 1274, 1092, 700, 352, 140, 42, 9, 1, 1430, 4368, 7280, 8400, 7460, 5392, 3262, 1664, 716, 256, 74, 16, 2, 4862, 18564, 38556, 56100, 63648, 59670, 47802, 33338, 20466, 11115
Offset: 0
Triangle begins:
0 : 1;
1 : 1;
2 : 2;
3 : 5, 1;
4 : 14, 8, 2;
5 : 42, 45, 25, 7, 1;
6 : 132, 220, 198, 112, 44, 12, 2;
7 : 429, 1001, 1274, 1092, 700, 352, 140, 42, 9, 1;
...
- Alois P. Heinz, Rows n = 0..50, flattened
- A. Claesson and T. Mansour, Counting occurrences of a pattern of type (1,2) or (2,1) in permutations, arXiv:math/0110036 [math.CO], 2001.
- S. Corteel, Crossings and alignments of permutations, Adv. Appl. Math 38 (2007) 149-163.
- FindStat - Combinatorial Statistic Finder, The number of nestings of a permutation, The number of crossings of a permutation
- R. Parviainen, Lattice Path Enumeration of Permutations with k Occurrences of the Pattern 2-13, Journal of Integer Sequences, Vol. 9 (2006), Article 06.3.2.
- Lucas Sá and Antonio M. García-García, The Wishart-Sachdev-Ye-Kitaev model: Q-Laguerre spectral density and quantum chaos, arXiv:2104.07647 [hep-th], 2021.
Columns k=0-10 give:
A000108,
A002696,
A094218,
A094219,
A120812,
A120813,
A120814,
A120815,
A120816,
A264496,
A264497.
-
b:= proc(u, o) option remember;
`if`(u+o=0, 1, add(b(u-j, o+j-1), j=1..u)+
add(expand(b(u+j-1, o-j)*x^(j-1)), j=1..o))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n, 0)):
seq(T(n), n=0..10); # Alois P. Heinz, Nov 14 2015
-
b[u_, o_] := b[u, o] = If[u+o == 0, 1, Sum[b[u-j, o+j-1], {j, 1, u}] + Sum[Expand[b[u+j-1, o-j]*x^(j-1)], {j, 1, o}]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, Exponent[p, x]}]][b[n, 0]]; Table[ T[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Jan 31 2016, after Alois P. Heinz *)
A303697
Number T(n,k) of permutations p of [n] whose difference between sum of up-jumps and sum of down-jumps equals k; triangle T(n,k), n>=0, min(0,1-n)<=k<=max(0,n-1), read by rows.
Original entry on oeis.org
1, 1, 1, 0, 1, 1, 1, 2, 1, 1, 1, 4, 5, 4, 5, 4, 1, 1, 11, 19, 19, 20, 19, 19, 11, 1, 1, 26, 82, 100, 101, 100, 101, 100, 82, 26, 1, 1, 57, 334, 580, 619, 619, 620, 619, 619, 580, 334, 57, 1, 1, 120, 1255, 3394, 4339, 4420, 4421, 4420, 4421, 4420, 4339, 3394, 1255, 120, 1
Offset: 0
Triangle T(n,k) begins:
: 1 ;
: 1 ;
: 1, 0, 1 ;
: 1, 1, 2, 1, 1 ;
: 1, 4, 5, 4, 5, 4, 1 ;
: 1, 11, 19, 19, 20, 19, 19, 11, 1 ;
: 1, 26, 82, 100, 101, 100, 101, 100, 82, 26, 1 ;
: 1, 57, 334, 580, 619, 619, 620, 619, 619, 580, 334, 57, 1 ;
Cf.
A000295,
A001720,
A005165,
A008292,
A081285,
A153229,
A291680,
A291684,
A291722,
A316292,
A316293,
A321316.
-
b:= proc(u, o) option remember; expand(`if`(u+o=0, 1,
add(b(u-j, o+j-1)*x^(-j), j=1..u)+
add(b(u+j-1, o-j)*x^( j), j=1..o)))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=ldegree(p)..degree(p)))(
`if`(n=0, 1, add(b(j-1, n-j), j=1..n))):
seq(T(n), n=0..12);
-
b[u_, o_] := b[u, o] = Expand[If[u+o == 0, 1,
Sum[b[u-j, o+j-1] x^-j, {j, 1, u}] +
Sum[b[u+j-1, o-j] x^j, {j, 1, o}]]];
T[0] = {1};
T[n_] := x^n Sum[b[j-1, n-j], {j, 1, n}] // CoefficientList[#, x]& // Rest;
T /@ Range[0, 12] // Flatten (* Jean-François Alcover, Feb 20 2021, after Alois P. Heinz *)
A316292
Number T(n,k) of permutations p of [n] such that k is the maximum of the partial sums of the signed up-down jump sequence of 0,p; triangle T(n,k), n>=0, ceiling((sqrt(1+8*n)-1)/2)<=k<=n, read by rows.
Original entry on oeis.org
1, 1, 2, 1, 5, 8, 16, 5, 50, 65, 1, 79, 314, 326, 69, 872, 2142, 1957, 34, 1539, 8799, 16248, 13700, 9, 1823, 24818, 89273, 137356, 109601, 1, 1494, 50561, 355271, 947713, 1287350, 986410, 856, 76944, 1070455, 4923428, 10699558, 13281458, 9864101
Offset: 0
Triangle T(n,k) begins:
: 1;
: 1;
: 2;
: 1, 5;
: 8, 16;
: 5, 50, 65;
: 1, 79, 314, 326;
: 69, 872, 2142, 1957;
: 34, 1539, 8799, 16248, 13700;
: 9, 1823, 24818, 89273, 137356, 109601;
: 1, 1494, 50561, 355271, 947713, 1287350, 986410;
-
b:= proc(u, o, c, k) option remember;
`if`(c>k, 0, `if`(u+o=0, 1,
add(b(u-j, o-1+j, c+j, k), j=1..u)+
add(b(u+j-1, o-j, c-j, k), j=1..o)))
end:
T:= (n, k)-> b(n, 0$2, k) -`if`(k=0, 0, b(n, 0$2, k-1)):
seq(seq(T(n, k), k=ceil((sqrt(1+8*n)-1)/2)..n), n=0..14);
-
b[u_, o_, c_, k_] := b[u, o, c, k] =
If[c > k, 0, If[u + o == 0, 1,
Sum[b[u - j, o - 1 + j, c + j, k], {j, 1, u}] +
Sum[b[u + j - 1, o - j, c - j, k], {j, 1, o}]]];
T[n_, k_] := b[n, 0, 0, k] - If[k == 0, 0, b[n, 0, 0, k - 1]];
Table[Table[T[n, k], {k, Ceiling[(Sqrt[8n+1]-1)/2], n}], {n, 0, 14}] // Flatten (* Jean-François Alcover, Feb 27 2021, after Alois P. Heinz *)
A316293
Number T(n,k) of permutations p of [n] such that k is the maximum of the partial sums of the signed up-down jump sequence of 0,p; triangle T(n,k), k>=0, k<=n<=k*(k+1)/2, read by columns.
Original entry on oeis.org
1, 1, 2, 1, 5, 8, 5, 1, 16, 50, 79, 69, 34, 9, 1, 65, 314, 872, 1539, 1823, 1494, 856, 339, 89, 14, 1, 326, 2142, 8799, 24818, 50561, 76944, 89546, 80938, 57284, 31771, 13707, 4520, 1103, 188, 20, 1, 1957, 16248, 89273, 355271, 1070455, 2514044, 4705648
Offset: 0
Triangle T(n,k) begins:
: 1;
: 1;
: 2;
: 1, 5;
: 8, 16;
: 5, 50, 65;
: 1, 79, 314, 326;
: 69, 872, 2142, 1957;
: 34, 1539, 8799, 16248, 13700;
: 9, 1823, 24818, 89273, 137356, 109601;
: 1, 1494, 50561, 355271, 947713, 1287350, 986410;
-
b:= proc(u, o, c, k) option remember;
`if`(c>k, 0, `if`(u+o=0, 1,
add(b(u-j, o-1+j, c+j, k), j=1..u)+
add(b(u+j-1, o-j, c-j, k), j=1..o)))
end:
T:= (n, k)-> b(n, 0$2, k) -`if`(k=0, 0, b(n, 0$2, k-1)):
seq(seq(T(n, k), n=k..k*(k+1)/2), k=0..8);
-
b[u_, o_, c_, k_] := b[u, o, c, k] = If[c > k, 0, If[u + o == 0, 1,
Sum[b[u - j, o - 1 + j, c + j, k], {j, 1, u}] +
Sum[b[u + j - 1, o - j, c - j, k], {j, 1, o}]]];
T[n_, k_] := b[n, 0, 0, k] - If[k == 0, 0, b[n, 0, 0, k - 1]];
Table[Table[T[n, k], {n, k, k(k+1)/2}], {k, 0, 8}] // Flatten (* Jean-François Alcover, Mar 14 2021, after Alois P. Heinz *)
A289489
Number of permutations p of [n] such that in 0p the sum of all jumps equals 2n.
Original entry on oeis.org
1, 0, 0, 1, 4, 15, 104, 644, 3696, 23388, 151842, 979110, 6445659, 43148963, 290832906, 1977914328, 13574296048, 93787977144, 651970844448, 4558718881927, 32038664402074, 226200869873851, 1603811085640698, 11415385190127413, 81538284501095235
Offset: 0
a(3) = 1: 312.
a(4) = 4: 3142, 4213, 4231, 4312.
a(5) = 15: 15234, 25134, 31542, 35124, 41235, 42153, 42531, 43152, 45123, 53214, 53241, 53421, 54213, 54231, 54312.
a(6) = 104: 126354, 136254, 142635, 146253, ..., 653421, 654213, 654231, 654312.
-
b:= proc(u, o) option remember; expand(`if`(u+o=0, 1,
add(b(u-j, o+j-1)*x^(j-1), j=1..u)+
add(b(u+j-1, o-j)*x^(j-1), j=1..o)))
end:
a:= n-> coeff(b(0, n), x, n):
seq(a(n), n=0..26);
-
b[u_, o_] := b[u, o] = Expand[If[u + o == 0, 1,
Sum[b[u - j, o + j - 1]*x^(j - 1), {j, 1, u}] +
Sum[b[u + j - 1, o - j]*x^(j - 1), {j, 1, o}]]];
a[n_] := Coefficient[b[0, n], x, n];
Table[a[n], {n, 0, 26}] (* Jean-François Alcover, Nov 17 2022, after Alois P. Heinz *)
Showing 1-6 of 6 results.
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