A264319
Number T(n,k) of permutations of [n] with exactly k (possibly overlapping) occurrences of the consecutive pattern 3412; triangle T(n,k), n>=0, 0<=k<=max(0,floor(n/2-1)), read by rows.
Original entry on oeis.org
1, 1, 2, 6, 23, 1, 110, 10, 631, 88, 1, 4223, 794, 23, 32301, 7639, 379, 1, 277962, 79164, 5706, 48, 2657797, 885128, 84354, 1520, 1, 27954521, 10657588, 1266150, 38452, 89, 320752991, 137752283, 19621124, 869740, 5461, 1, 3987045780, 1904555934, 316459848
Offset: 0
T(4,1) = 1: 3412.
T(5,1) = 10: 14523, 24513, 34125, 34512, 35124, 43512, 45123, 45132, 45231, 53412.
T(6,2) = 1: 563412.
T(7,2) = 23: 1674523, 2674513, 3674512, 4673512, 5614723, 5624713, 5634127, 5634712, 5673412, 5714623, 5724613, 5734126, 5734612, 6573412, 6714523, 6724513, 6734125, 6734512, 6735124, 6745123, 6745132, 6745231, 7563412.
T(8,3) = 1: 78563412.
T(9,3) = 48: 189674523, 289674513, 389674512, ..., 896745132, 896745231, 978563412.
Triangle T(n,k) begins:
00 : 1;
01 : 1;
02 : 2;
03 : 6;
04 : 23, 1;
05 : 110, 10;
06 : 631, 88, 1;
07 : 4223, 794, 23;
08 : 32301, 7639, 379, 1;
09 : 277962, 79164, 5706, 48;
10 : 2657797, 885128, 84354, 1520, 1;
Columns k=0-10 give:
A113229,
A264320,
A264321,
A264322,
A264323,
A264324,
A264325,
A264326,
A264327,
A264328,
A264329.
-
b:= proc(u, o, t) option remember; `if`(u+o=0, 1, add(expand(
b(u+j-1, o-j, j)*`if`(t<0 and j<1-t, x, 1)), j=1..o)+
add(b(u-j, o+j-1, `if`(t>0 and j>t, t-j, 0)), j=1..u))
end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n, 0$2)):
seq(T(n), n=0..14);
-
b[u_, o_, t_] := b[u, o, t] = If[u+o == 0, 1, Sum[Expand[b[u+j-1, o-j, j]*If[t<0 && j<1-t, x, 1]], {j, 1, o}] + Sum[b[u-j, o+j-1, If[t>0 && j>t, t-j, 0]], {j, 1, u}]]; T[n_] := Function[p, Table[Coefficient[p, x, i], {i, 0, Exponent[p, x]}]][b[n, 0, 0]]; Table[T[n], {n, 0, 14}] // Flatten (* Jean-François Alcover, Jan 16 2017, translated from Maple_ *)
A061206
a(n) = total number of occurrences of the consecutive pattern 1324 in all permutations of [n+3].
Original entry on oeis.org
1, 10, 90, 840, 8400, 90720, 1058400, 13305600, 179625600, 2594592000, 39956716800, 653837184000, 11333177856000, 207484333056000, 4001483566080000, 81096733605888000, 1723305589125120000, 38318206628782080000, 889833909490606080000, 21543347282404147200000
Offset: 1
Melvin J. Knight (knightmj(AT)juno.com), May 30 2001
a(4)=840 because 4*(7!)/24 = 4*7*6*5 = 840.
-
[n*Factorial(n+3)/24: n in [1..20]]; // Vincenzo Librandi, Oct 11 2011
-
a := n -> n!*binomial(-n,4): seq(a(n),n=1..20); # Peter Luschny, Apr 29 2016
-
Array[# (# + 3)!/24 &, 20] (* or *) Array[#!*Binomial[-#, 4] &, 20] (* Michael De Vlieger, Sep 30 2017 *)
-
a(n) = n*(n+3)!/24; \\ Altug Alkan, Oct 08 2017
-
[binomial(n,4)*factorial (n-3) for n in range(4, 21)] # Zerinvary Lajos, Jul 07 2009
A113228
a(n) is the number of permutations of [1..n] that avoid the consecutive pattern 1324 (equally, the permutations that avoid 4231).
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 632, 4229, 32337, 278204, 2659223, 27959880, 320706444, 3985116699, 53328433923, 764610089967, 11693644958690, 190015358010114, 3269272324528547, 59373764638615449, 1135048629795612125, 22783668363316052016, 479111084084119883217
Offset: 0
In 24135, the entries 2435 are in relative order 1324 but they do not occur consecutively and 24135 avoids the consecutive 1324 pattern.
- Alois P. Heinz, Table of n, a(n) for n = 0..200 (terms n = 0..60 from Ray Chandler)
- Andrew Baxter, Brian Nakamura, and Doron Zeilberger, Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes
- Colin Defant, Noah Kravitz, and Nathan Williams, The Ungar Games, arXiv:2302.06552 [math.CO], 2023.
- Sergi Elizalde, Asymptotic enumeration of permutations avoiding generalized patterns, arXiv:math/0505254 [math.CO], 2005.
- Sergi Elizalde, Asymptotic enumeration of permutations avoiding generalized patterns, Adv. in Appl. Math. 36 (2006), no. 2, 138-155.
- Sergi Elizalde and Marc Noy, Consecutive patterns in permutations, Adv. Appl. Math. 30 (2003), 110-125.
- Steven Finch, Pattern-Avoiding Permutations [Broken link?]
- Steven Finch, Pattern-Avoiding Permutations [Cached copy, with permission]
-
b:= proc(u, o, t) option remember; `if`(u+o=0, 1,
add(b(u-j, o+j-1, `if`(t>0 and j b(n, 0, 0):
seq(a(n), n=0..25); # Alois P. Heinz, Nov 07 2013
-
Clear[u, v, w]; w[0]=1; w[1]=1;w[2]=2; w[n_]/;n>=3 := w[n] = Sum[w[n, a], {a, n}]; w[1, 1] = w[2, 1] = w[2, 2] = 1; w[n_, a_]/;n>=3 && 1<=a<=n := Sum[u[n, a, b], {b, a+1, n}] + v[n, a]; v[1, 1]=1; v[n_, a_]/;n>=2 && a==1 := 0; v[n_, a_]/;n>=2 && 2<=a<=n := wCumulative[n-1, a-1]; wCumulative[n_, k_]/;Not[1<=k<=n] := 0; wCumulative[n_, k_]/;1<=k<=n := wCumulative[n, k] = Sum[w[n, a], {a, k}]; u[n_, a_, b_]/;Not[1<=a=4 && 1<=a0 && j < t, -j, 0]], {j, 1, u}] + Sum[b[u+j-1, o-j, j], {j, 1, If[t<0, Min[-t-1, o], o]}]]; a[n_] := b[n, 0, 0]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Jan 19 2017, after Alois P. Heinz *)
A264174
Number of permutations of [n] with exactly one occurrence of the consecutive pattern 1324.
Original entry on oeis.org
1, 10, 86, 782, 7571, 78726, 882997, 10657118, 137977980, 1910131680, 28178987795, 441555002430, 7326966011380, 128386409972224, 2369404379818067, 45945570232645676, 934057289766619391, 19867567809865839562, 441307130768553551181, 10218971845916640741804
Offset: 4
a(4) = 1: 1324.
a(5) = 10: 12435, 13245, 13254, 14253, 14352, 21435, 24351, 31425, 41325, 51324.
A264175
Number of permutations of [n] with exactly two (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
2, 29, 407, 5856, 84351, 1251246, 19318314, 311306106, 5247587002, 92593553775, 1709675651881, 33009644160452, 665774603385155, 14011066071814409, 307285854478257587, 7014599706534263680, 166463062283304010885, 4101715354110043233880, 104819153609360857542346
Offset: 6
a(6) = 2: 132546, 142536.
a(7) = 29: 1243657, 1253647, 1324657, 1325467, 1325476, 1326475, 1326574, 1425367, 1425376, 1426375, 1426573, 1436572, 1526374, 1526473, 1536472, 2143657, 2153647, 2436571, 2536471, 3142657, 3152647, 4132657, 4152637, 5132647, 5142637, 6132547, 6142537, 7132546, 7142536.
A264176
Number of permutations of [n] with exactly three (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
5, 94, 2215, 48234, 984498, 20018292, 410686782, 8572433100, 183327724185, 4031683382270, 91372697900165, 2136865477317678, 51598608241844089, 1286708862328929178, 33133108712407230345, 880758960967930222782, 24159154493395236208028, 683464289463119208686060
Offset: 8
a(8) = 5: 13254768, 13264758, 14253768, 14263758, 15263748.
A264177
Number of permutations of [n] with exactly four (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
14, 322, 14322, 446883, 12483967, 338673045, 9001362380, 238129970970, 6339260568095, 170856651003305, 4682542114588253, 130886424229747444, 3738852184485065063, 109293382675549834910, 3272185613468650581758, 100391722311294374198126, 3157137371183609019647618
Offset: 10
A264178
Number of permutations of [n] with exactly five (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
42, 1140, 111599, 4611558, 173158550, 6150882796, 207804108053, 6856445861216, 223949186168735, 7301452481956954, 239153348717534527, 7905330813488457406, 264571946551458787730, 8986227993271868092040, 310292223622481235050006, 10906047958204275121950876
Offset: 12
A264179
Number of permutations of [n] with exactly six (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
132, 4125, 1020505, 51702016, 2624962373, 120276735039, 5090983012009, 207018756962968, 8203026471635019, 320184726894303006, 12416042942124295046, 481161485425852541912, 18716816000121904713776, 733252038482676120349158, 29003355422362252267923702
Offset: 14
A264180
Number of permutations of [n] with exactly seven (possibly overlapping) occurrences of the consecutive pattern 1324.
Original entry on oeis.org
429, 15158, 10456115, 614782886, 43495122923, 2526575343670, 132579863515715, 6585406452179450, 313695654024665114, 14537292870957416456, 662270871072941918072, 29874010431593104928640, 1341720576566678207783742, 60253806120517563450850104
Offset: 16
Showing 1-10 of 13 results.
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