A147681
Late-growing permutations: number of permutations of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 1, 1, 3, 7, 35, 139, 1001, 5701, 53109, 402985, 4605271, 43665667, 589809987, 6735960079, 104899483845, 1402547616085, 24698838710457, 378845419610773, 7444522779300351, 128830635114146047, 2792467448952670671, 53854927962971227495, 1276369340371154144337, 27141331409803338993193, 698008560075731437652425, 16228797258964121571885457, 450111715263775132783135875
Offset: 0
This is the first of 19 related sequences, the others being
A147682,
A147684,
A147686,
A147687,
A147692,
A147694,
A147695,
A147697,
A147698,
A147700,
A147705,
A147707,
A147712,
A147713,
A147714,
A147715,
A147717,
A147769.
-
a:= proc(n) option remember; local b, m; m:= n*(n+1)/2;
b:= proc(s) option remember; local h, g; h:= nops(s);
g:= (n-h+1)*(1+n)/2 -m +add(i, i=s); `if`(h<2, 1,
add(`if`(s[i]<=g, b(subsop(i=NULL, s)), 0), i=1..h))
end; forget(b);
b([$1..n])
end:
seq(a(n), n=0..15); # Alois P. Heinz, Aug 10 2012
-
a[n_] := a[n] = Module[{b, m}, m = n*(n+1)/2; b[s_List] := b[s] = Module[{h, g}, h = Length[s]; g = (n-h+1)*(1+n)/2 - m + Total[s]; If[h<2, 1, Sum[If[s[[i]] <= g, b[ReplacePart[s, i -> Sequence[]]], 0], {i, 1, h}]]]; b[Range[n]]]; Table[a[n], {n, 0, 15}] (* Jean-François Alcover, Mar 13 2015, after Alois P. Heinz *)
A007004
a(n) = (3*n)! / ((n+1)*(n!)^3).
Original entry on oeis.org
1, 3, 30, 420, 6930, 126126, 2450448, 49884120, 1051723530, 22787343150, 504636071940, 11377249621920, 260363981732400, 6034149862347600, 141371511060715200, 3343436236585914480, 79726203788589122490, 1914992149823954412750, 46295775130831740013500
Offset: 0
n=1, three walks: NE(SW), (SW)NE, N(SW)E. - _Shanzhen Gao_, Nov 09 2010
- N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
-
[Factorial(3*n) / ((n+1)*Factorial(n)^3): n in [0..30]]; // Vincenzo Librandi, May 26 2011
-
seq(binomial(2*n,n)*binomial(3*n,n)/(n+1), n=0..20); # Zerinvary Lajos, May 27 2006
-
a[n_]:=(3*n)!/((n + 1)*(n!)^3); (* Vladimir Joseph Stephan Orlovsky, Dec 13 2008 *)
CoefficientList[Series[Hypergeometric2F1[1/3,2/3,2,27 x],{x,0,20}],x] (* Harvey P. Dale, Apr 07 2013 *)
Table[Multinomial[n, n, n]/(n + 1), {n, 0, 12}] (* Emanuele Munarini, Oct 25 2016 *)
-
makelist(multinomial_coeff(n,n,n)/(n+1),n,0,24); /* Emanuele Munarini, Oct 25 2016 */
A147682
Late-growing permutations: number of permutations of 2 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 1, 2, 30, 403, 18720, 746192, 71892912, 5873837638, 951265850580, 133244998049858, 32484245570649180, 6956417433946216990, 2375465385671586163800, 723157816455776560763294, 329255781245519867317200240, 135189844328107458501296074066, 79079768375837127458516103725820
Offset: 0
-
b:= proc(l) option remember; local m, n, g;
m, n:= nops(l), add(i, i=l);
g:= add(i*l[i], i=1..m)-(m+1)/2*(n-1);
`if`(n<2, 1, add(`if`(l[i]>0 and i<=g,
b(subsop(i=l[i]-1, l)), 0), i=1..m))
end:
a:= n-> b([2$n]):
seq(a(n), n=1..10); # Alois P. Heinz, Aug 16 2012
-
b[l_List] := b[l] = Module[{m, n, g}, {m, n} = {Length[l], Total[l]}; g = Sum[i* l[[i]], {i, 1, m}] - (m+1)/2*(n-1); If[n<2, 1, Sum[If[l[[i]]>0 && i <= g, b[ ReplacePart[l, i -> l[[i]]-1]], 0], {i, 1, m}]]]; a[n_] := b[Table[2, {n}]]; Table[a[n], {n, 0, 10}] (* Jean-François Alcover, Mar 13 2015, after Alois P. Heinz *)
A147684
Late-growing permutations: number of permutations of 3 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 1, 5, 420, 40350, 19369350, 9212531290, 13126885205000, 17810026933803520, 55560479543584645500, 164686892656273830526336, 953018107457232657556038400
Offset: 0
A147686
Late-growing permutations: number of permutations of 4 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 14, 6930, 5223915, 27032968200, 164401445439455, 3627155158988429250, 86733224358763671877835, 5469038805616093755410863500
Offset: 1
A147687
Late-growing permutations: number of permutations of 5 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 42, 126126, 783353872, 44776592395920, 3611684199828856072, 1267664556730792079292048, 551951935901513814954541886968
Offset: 1
A147692
Late-growing permutations: number of permutations of 6 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 132, 2450448, 129141898872, 82881380383401600, 90695437030756958966384, 515544601327354412382720479328, 4172457328749067883416103335334343279
Offset: 1
A147694
Late-growing permutations: number of permutations of 7 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 429, 49884120, 22745605840236, 165850226337286576800, 2500267880518574604245088816, 233099041543988273824859604028713600
Offset: 1
A147695
Late-growing permutations: number of permutations of 8 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 1430, 1051723530, 4206489449301315, 351597937025844947295000, 73839261438738554611424321993670
Offset: 1
A147697
Late-growing permutations: number of permutations of 9 indistinguishable copies of 1..n with every partial sum <= the same partial sum averaged over all permutations.
Original entry on oeis.org
1, 4862, 22787343150, 807660192541534200, 779279938350147159519336600, 2299118288652572230673921886739695630
Offset: 1
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