A117158
Number of permutations avoiding the consecutive pattern 1234.
Original entry on oeis.org
1, 1, 2, 6, 23, 111, 642, 4326, 33333, 288901, 2782082, 29471046, 340568843, 4263603891, 57482264322, 830335952166, 12793889924553, 209449977967081, 3630626729775362, 66429958806679686, 1279448352687538463, 25874432578888440471, 548178875969847203202
Offset: 0
- F. N. David and D. E. Barton, Combinatorial Chance, Hafner, New York, 1962, pages 156-157.
- Alois P. Heinz, Table of n, a(n) for n = 0..450 (terms n = 0..60 from Ray Chandler)
- A. Baxter, B. Nakamura, and D. Zeilberger, Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes.
- Sergi Elizalde, Asymptotic enumeration of permutations avoiding generalized patterns, Adv. Appl. Math. 36 (2006), 138-155.
- Sergi Elizalde and Marc Noy, Consecutive patterns in permutations, Adv. Appl. Math. 30 (2003), 110-125.
- Steven Finch, Pattern-Avoiding Permutations. [Archived version]
- Steven Finch, Pattern-Avoiding Permutations. [Cached copy, with permission]
- Ira M. Gessel, Symmetric functions and P-recursiveness, J. Combin. Theory A 53 (1990), 257-285.
- Ira M. Gessel, Yan Zhuang, Counting permutations by alternating descents, arXiv:1408.1886 [math.CO], 2014. See displayed equation before Eq. (3) and set m=4. - _N. J. A. Sloane_, Aug 11 2014
- Kaarel Hänni, Asymptotics of descent functions, arXiv:2011.14360 [math.CO], Nov 29 2020, p. 14.
- Mingjia Yang, Doron Zeilberger, Increasing Consecutive Patterns in Words, arXiv:1805.06077 [math.CO], 2018.
- Mingjia Yang, An experimental walk in patterns, partitions, and words, Ph. D. Dissertation, Rutgers University (2020).
Cf.
A022558,
A049774,
A111004,
A113228,
A113229,
A117156,
A117226,
A177523,
A177533,
A201692,
A201693,
A230051,
A324132.
-
b:= proc(u, o, t) option remember; `if`(u+o=0, 1,
`if`(t<2, add(b(u+j-1, o-j, t+1), j=1..o), 0)+
add(b(u-j, o+j-1, 0), j=1..u))
end:
a:= n-> b(n, 0, 0):
seq(a(n), n=0..30); # Alois P. Heinz, Oct 07 2013
-
a[n_]:=Coefficient[Series[2/(Cos[x]-Sin[x]+Exp[ -x]),{x,0,30}],x^n]*n!
(* second program: *)
b[u_, o_, t_] := b[u, o, t] = If[u+o==0, 1, If[t<2, Sum[b[u+j-1, o-j, t+1], {j, 1, o}], 0] + Sum[b[u-j, o+j-1, 0], {j, 1, u}]]; a[n_] := b[n, 0, 0]; Table[a[n], {n, 0, 30}] (* Jean-François Alcover, Nov 23 2015, after Alois P. Heinz *)
A117156
Number of permutations avoiding the consecutive pattern 1342.
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 630, 4210, 32150, 276210, 2636720, 27687440, 317169270, 3936056080, 52603684760, 753241509900, 11504852242400, 186705357825800, 3208160592252000, 58188413286031600, 1110946958902609400
Offset: 0
- Sergi Elizalde, Asymptotic enumeration of permutations avoiding generalized patterns, Adv. Appl. Math. 36 (2006) 138-155.
- Sergi Elizalde and Marc Noy, Consecutive patterns in permutations, Adv. Appl. Math. 30 (2003) 110-125.
-
a[n_]:=Coefficient[Series[1/(1-Integrate[Exp[ -t^3/6],{t,0,x}]),{x,0,30}],x^n]*n!
(* Second program: *)
m = 21; gf = 1/(1-Sum[If[Mod[k, 3] == 0, (-1)^Mod[k, 6]/(6^(k/3)*(k/3)!), 0]* (x^(k+1)/(k+1)), {k, 0, m}]);
CoefficientList[gf + O[x]^m, x]*Range[0, m-1]! (* Jean-François Alcover, May 11 2019 *)
A264173
Number T(n,k) of permutations of [n] with exactly k (possibly overlapping) occurrences of the consecutive pattern 1324; 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, 632, 86, 2, 4229, 782, 29, 32337, 7571, 407, 5, 278204, 78726, 5856, 94, 2659223, 882997, 84351, 2215, 14, 27959880, 10657118, 1251246, 48234, 322, 320706444, 137977980, 19318314, 984498, 14322, 42, 3985116699, 1910131680, 311306106
Offset: 0
T(4,1) = 1: 1324.
T(6,2) = 2: 132546, 142536.
T(8,3) = 5: 13254768, 13264758, 14253768, 14263758, 15263748.
T(10,4) = 14: 132547698(10), 132548697(10), 132647598(10), 132648597(10), 132748596(10), 142537698(10), 142538697(10), 142637598(10), 142638597(10), 142738596(10), 152637498(10), 152638497(10), 152738496(10), 162738495(10).
Triangle T(n,k) begins:
00 : 1;
01 : 1;
02 : 2;
03 : 6;
04 : 23, 1;
05 : 110, 10;
06 : 632, 86, 2;
07 : 4229, 782, 29;
08 : 32337, 7571, 407, 5;
09 : 278204, 78726, 5856, 94;
10 : 2659223, 882997, 84351, 2215, 14;
Columns k=0-10 give:
A113228,
A264174,
A264175,
A264176,
A264177,
A264178,
A264179,
A264180,
A264181,
A264182,
A264183.
T(2n+2,n) gives
A000108(n) for n>0.
-
b:= proc(u, o, t) option remember; expand(`if`(u+o=0, 1,
add(b(u-j, o+j-1, `if`(t>0 and j (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] = Expand[If[u + o == 0, 1, Sum[b[u - j, o + j - 1, If[t > 0 && j < t, -j, 0]], {j, 1, u}] + Sum[b[u + j - 1, o - j, j] * If[t < 0 && -j <= t, x, 1], {j, 1, o}]]];
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, Apr 30 2017, translated from Maple *)
A117226
Number of permutations of [n] avoiding the consecutive pattern 1243.
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 630, 4204, 32054, 274914, 2619692, 27459344, 313990182, 3889585408, 51888955808, 741668212080, 11307669002720, 183174676857608, 3141820432768752, 56882461258572976, 1084056190235653304, 21692744773505849952, 454758269790599361968
Offset: 0
- Alois P. Heinz, Table of n, a(n) for n = 0..200 (terms n = 0..60 from Ray Chandler)
- A. Baxter, B. Nakamura, and D. Zeilberger, Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes, 2011.
- Sergi Elizalde and Marc Noy, Consecutive patterns in permutations, Adv. Appl. Math. 30 (2003), 110-125; see p. 120.
- 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. Appl. Math. 36 (2006), 138-155.
- Steven Finch, Pattern-Avoiding Permutations. [Archived copy]
- Steven Finch, Pattern-Avoiding Permutations. [Cached copy, with permission]
- Eric Weisstein's World of Mathematics, Pochhammer Symbol.
- Wikipedia, Falling and rising factorials.
-
b:= proc(u, o, t) option remember; `if`(u+o=0, 1,
add(b(u-j, o+j-1, 0), j=`if`(t<0, -t, 1)..u)+
add(b(u+j-1, o-j, `if`(t=0, j, -j)), j=1..o))
end:
a:= n-> b(n, 0$2):
seq(a(n), n=0..25); # Alois P. Heinz, Nov 07 2013
-
A[x_]:=Integrate[AiryAi[ -t],{t,0,x}]; B[x_]:=Integrate[AiryBi[ -t],{t,0,x}];
c=-3^(2/3)*Gamma[2/3]/2; d=-3^(1/6)*Gamma[2/3]/2;
a[n_]:=SeriesCoefficient[1/(c*A[x]+d*B[x]+1),{x,0,n}]*n!; Table[a[n],{n,0,10}] (* fixed by Vaclav Kotesovec, Aug 23 2014 *)
(* constant d: *) 1/x/.FindRoot[3^(2/3)*Gamma[2/3]/2 * Integrate[AiryAi[-t],{t,0,x}] + 3^(1/6)*Gamma[2/3]/2 * Integrate[AiryBi[-t],{t,0,x}]==1,{x,1},WorkingPrecision->50] (* Vaclav Kotesovec, Aug 23 2014 *)
A113229
Number of permutations avoiding the consecutive pattern 3412.
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 631, 4223, 32301, 277962, 2657797, 27954521, 320752991, 3987045780, 53372351265, 765499019221, 11711207065229, 190365226548070, 3276401870322033, 59523410471007913, 1138295039078030599, 22856576346825690128, 480807130959249565541
Offset: 0
The 5! - a(5) = 10 permutations on [5] not counted by a(5) are 14523, 24513, 34125, 34512, 35124, 43512, 45123, 45132, 45231, 53412.
- Alois P. Heinz, Table of n, a(n) for n = 0..200 (terms n = 0..60 from Ray Chandler)
- A. Baxter, B. Nakamura, and D. Zeilberger. Automatic generation of theorems and proofs on enumerating consecutive Wilf-classes
- V. Dotsenko and A. Khoroshkin, Shuffle algebras, homology, and consecutive pattern avoidance, arXiv preprint arXiv:1109.2690 [math.CO], 2011.
- 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.
- S. Elizalde and M. 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>t, t-j, 0)), j=1..u)+
add(b(u+j-1, o-j, j), j=`if`(t<0,1-t,1)..o))
end:
a:= n-> b(n, 0$2):
seq(a(n), n=0..25); # Alois P. Heinz, Nov 07 2013
-
b[u_, o_, t_] := b[u, o, t] = If[u+o == 0, 1, Sum[b[u-j, o+j-1, If[t>0 && j>t, t-j, 0]], {j, 1, u}] + Sum[b[u+j-1, o-j, j], {j, Range[If[t<0, 1-t, 1], o]}]]; a[n_] := b[n, 0, 0]; Table[a[n], {n, 0, 25}] (* Jean-François Alcover, Mar 13 2015, after Alois P. Heinz *)
A201692
Number of permutations that avoid the consecutive pattern 1423.
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 631, 4218, 32221, 276896, 2643883, 27768955, 318174363, 3949415431, 52794067318, 756137263377, 11551672922816, 187507250145806, 3222662529113641, 58464560588277289, 1116469710152742025, 22386721651323946628, 470259350616967829363
Offset: 0
-
c := proc(n,l)
if n = 1 then
if l = 0 then
1;
else
0;
end if;
elif n= 2 or n = 3 then
0;
else
a := 0 ;
for k from 1 to (n-2)/2 do
a := a+procname(n-2*k-1,l-k)*binomial(n-k-2,k) ;
end do:
a ;
end if;
end proc:
A201693 := proc(nmax)
g := 1-t ;
for n from 2 to nmax do
for l from 0 to n/2 do
g := g-c(n,l)*t^n*(-1)^l/n! ;
end do:
end do:
taylor(1/g,t=0,nmax) ;
end proc:
nmax := 25 ;
egf := A201693(nmax) ;
for n from 0 to nmax-1 do
printf("%d,",coeftayl(egf,t=0,n)*n!) ;
end do: # R. J. Mathar, Dec 04 2011
# second Maple program:
b:= proc(u, o, t) option remember; `if`(u+o=0, 1,
add(b(u-j, o+j-1, `if`(0 b(n, 0$2):
seq(a(n), n=0..25); # Alois P. Heinz, Nov 07 2013
-
b[u_, o_, t_] := b[u, o, t] = If[u+o == 0, 1, Sum[b[u-j, o+j-1, If[0Jean-François Alcover, Mar 18 2014, after Alois P. Heinz *)
A201693
Number of permutations that avoid the consecutive pattern 2413.
Original entry on oeis.org
1, 1, 2, 6, 23, 110, 632, 4237, 32465, 279828, 2679950, 28232972, 324470844, 4039771856, 54165468774, 778128659247, 11923645252411, 194131328012012, 3346615262190736, 60897160676005110, 1166446154857250412, 23459656378909613446, 494290181112325561351
Offset: 0
A231166
Number of permutations of [n] avoiding simultaneously consecutive patterns 1243, 1342, and 1324.
Original entry on oeis.org
1, 1, 2, 6, 21, 91, 467, 2755, 18523, 139740, 1169616, 10763807, 108028386, 1174391384, 13748315494, 172439034531, 2306986699190, 32792999417180, 493559520202535, 7841127918788283, 131127477517244419, 2302491655047553206, 42355105188617740229
Offset: 0
a(4) = 24 - 3 = 21 because 1243, 1342, 1324 are avoided.
-
b:= proc(u, o, s, t) option remember; `if`(u+o=0, 1,
add(b(u-j, o+j-1, `if`(t>0, t, 0), `if`(t>0, -j, 0)),
j=`if`(s>0 and t>0,s+t-1,1)..u)+
add(b(u+j-1, o-j, `if`(t>0, t, 0), +j),
j=1..`if`(s>0 and t<0 and -t b(n, 0$3):
seq(a(n), n=0..25);
-
b[u_, o_, s_, t_] := b[u, o, s, t] = If[u + o == 0, 1, Sum[b[u - j, o + j - 1, If[t > 0, t, 0], If[t > 0, -j, 0]], {j, If[s > 0 && t > 0, s + t - 1, 1], u}] + Sum[b[u + j - 1, o - j, If[t > 0, t, 0], +j], {j, 1, If[s > 0 && t < 0 && -t < s, -t - 1, o]}]];
a[n_] := b[n, 0, 0, 0];
a /@ Range[0, 25] (* Jean-François Alcover, Feb 27 2020, after Alois P. Heinz *)
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