A349153
Numbers k such that the k-th composition in standard order has sum equal to twice its reverse-alternating sum.
Original entry on oeis.org
0, 11, 12, 14, 133, 138, 143, 148, 155, 158, 160, 168, 179, 182, 188, 195, 198, 204, 208, 216, 227, 230, 236, 240, 248, 2057, 2066, 2071, 2077, 2084, 2091, 2094, 2101, 2106, 2111, 2120, 2131, 2134, 2140, 2149, 2154, 2159, 2164, 2171, 2174, 2192, 2211, 2214
Offset: 1
The terms and corresponding compositions begin:
0: ()
11: (2,1,1)
12: (1,3)
14: (1,1,2)
133: (5,2,1)
138: (4,2,2)
143: (4,1,1,1,1)
148: (3,2,3)
155: (3,1,2,1,1)
158: (3,1,1,1,2)
160: (2,6)
168: (2,2,4)
179: (2,1,3,1,1)
182: (2,1,2,1,2)
188: (2,1,1,1,3)
These compositions are counted by
A262977 up to 0's.
The unreversed negative version is
A349154.
A non-reverse unordered version is
A349159, counted by
A000712 up to 0's.
A003242 counts Carlitz compositions.
A025047 counts alternating or wiggly compositions, complement
A345192.
A116406 counts compositions with alternating sum >=0, ranked by
A345913.
A138364 counts compositions with alternating sum 0, ranked by
A344619.
Cf.
A000070,
A000346,
A001250,
A001700,
A008549,
A027306,
A058622,
A088218,
A114121,
A120452,
A294175.
Statistics of standard compositions:
- The compositions themselves are the rows of
A066099.
- Heinz number is given by
A333219.
Classes of standard compositions:
-
stc[n_]:=Differences[ Prepend[Join@@Position[ Reverse[IntegerDigits[n,2]],1],0]]//Reverse;
sats[y_]:=Sum[(-1)^(i-Length[y])*y[[i]],{i,Length[y]}];
Select[Range[0,1000],Total[stc[#]]==2*sats[stc[#]]&]
A115982
Number of planar partitions that are not corners.
Original entry on oeis.org
0, 0, 0, 1, 3, 10, 23, 54, 112, 228, 437, 826, 1499, 2685, 4688, 8079, 13668, 22875, 37738, 61676, 99672, 159742, 253681, 399962, 625741, 972756, 1502302, 2306988, 3522492, 5351239, 8088469, 12170163, 18229411, 27192571
Offset: 1
The planar partitions begin 1 3 6 13 24 48 ... A000219 with corners 1 3 6 12 21 38 ... A006330; therefore the present sequence begins 0 0 0 1 3 10 ...
A288578
q-Expansion of wedge character chi^(2)(q).
Original entry on oeis.org
1, 2, 5, 9, 18, 31, 55, 91, 151, 240, 381, 587, 900, 1352, 2018, 2966, 4332, 6250, 8962, 12725, 17962, 25147, 35015, 48414, 66603, 91071, 123945, 167786, 226154, 303375, 405337, 539249, 714740, 943659, 1241605, 1627812, 2127302, 2770966, 3598567
Offset: 0
-
chi := proc(l,e)
local gf,m,n,f;
gf := 0 ;
for m from 0 to e+1 do
f := 1;
for n from 1 to min(m+abs(l),e-m+1) do
f := f/(1-q^n) ;
end do:
for n from 1 to min(m,e-m+1) do
f := f/(1-q^n) ;
end do:
gf := gf+f*q^m ;
end do:
expand(gf) ;
coeftayl(%,q=0,e) ;
end proc:
A288578 := proc(n)
chi(2,n) ;
end proc:
for n from 0 do
printf("%d,\n",A288578(n)) ;
end do: # R. J. Mathar, Jul 04 2017
A110582
Triangle, read by rows, where the g.f. of diagonal n, D_n(x), is generated from the g.f. of row n-1, R_{n-1}(x), by D_n(x) = R_{n-1}(x)/(1-x)^2 for n>0, with D_0(x) = 1/(1-x)^2.
Original entry on oeis.org
1, 1, 2, 1, 2, 3, 1, 4, 3, 4, 1, 4, 7, 4, 5, 1, 6, 10, 10, 5, 6, 1, 6, 14, 16, 13, 6, 7, 1, 8, 18, 26, 22, 16, 7, 8, 1, 8, 25, 34, 38, 28, 19, 8, 9, 1, 10, 29, 52, 55, 50, 34, 22, 9, 10, 1, 10, 37, 66, 84, 76, 62, 40, 25, 10, 11, 1, 12, 44, 90, 116, 122, 97, 74, 46, 28, 11, 12
Offset: 0
Triangle begins:
1;
1,2;
1,2,3;
1,4,3,4;
1,4,7,4,5;
1,6,10,10,5,6;
1,6,14,16,13,6,7;
1,8,18,26,22,16,7,8;
1,8,25,34,38,28,19,8,9;
1,10,29,52,55,50,34,22,9,10; ...
Row sums form A006330 (offset 1):
{1,3,6,12,21,38,63,106,170,272,422,653,...},
(planar partitions with only one row and one column).
G.f. of diagonal n, D_n(x), is generated from g.f. of
row n-1, R_{n-1}(x), by D_n(x) = R_{n-1}(x)/(1-x)^2:
D_3(x) = 1 + 4*x + 10*x^2 + 16*x^3 + 22*x^4 + ...
= (1 + 2*x + 3*x^2)/(1-x)^2 = R_2(x)/(1-x)^2;
D_4(x) = 1 + 6*x + 14*x^2 + 26*x^3 + 38*x^4 + ...
= (1+ 4*x+ 3*x^2+ 4*x^3)/(1-x)^2 = R_3(x)/(1-x)^2.
-
T[n_, k_] := T[n, k] = If[n < k || k < 0, 0, If[k == 0, 1, If[k == n, n + 1, Sum[T[n - k - 1, j]*(k - j + 1), {j, 0, k}]]]]; Table[T[n, k], {n, 0, 20}, {k, 0, n}] // Flatten (* G. C. Greubel, Sep 01 2017 *)
-
T(n,k)=if(n
-
T(n,k)=local(X=x+x*O(x^n),Y=y+y*O(y^k));if(n
Original entry on oeis.org
1, 0, 0, 0, 1, 4, 15, 40, 103, 238, 531, 1131, 2362, 4811, 9694, 19307, 38243, 75400, 148443, 291984, 574724, 1132368, 2234617, 4416937, 8745567, 17343737, 34446090, 68500682, 136374947, 271755878, 541950747, 1081467319, 2159170372, 4312555339, 8616279482, 17219151572, 34418065540, 68805730450, 137566021077
Offset: 0
a(8) = 103 because A011782(8) + A000219(8) - A000712(8) = 128 + 160 - 185.
-
N=66; x='x+O('x^N);
gf011782 =(1-x)/(1-2*x);
gf000219 = 1/prod(n=1,N, (1-x^n)^n );
gf000712 = 1/eta(x)^2;
Vec( gf011782 + gf000219 - gf000712 )
\\ Joerg Arndt, Mar 25 2014
A259100
Triangle read by rows, arising in the enumeration of corners.
Original entry on oeis.org
1, 0, 1, 0, 2, 1, 0, 3, 2, 1, 0, 4, 5, 2, 1, 0, 5, 8, 5, 2, 1, 0, 6, 14, 10, 5, 2, 1, 0, 7, 20, 18, 10, 5, 2, 1, 0, 8, 30, 30, 20, 10, 5, 2, 1
Offset: 0
Triangle begins:
1;
0, 1;
0, 2, 1;
0, 3, 2, 1;
0, 4, 5, 2, 1;
0, 5, 8, 5, 2, 1;
0, 6, 14, 10, 5, 2, 1;
0, 7, 20, 18, 10, 5, 2, 1;
0, 8, 30, 30, 20, 10, 5, 2, 1;
...
A259101
Square array read by antidiagonals arising in the enumeration of corners.
Original entry on oeis.org
1, 2, 2, 5, 16, 5, 14, 91, 91, 14, 42, 456, 936, 456, 42, 132, 2145, 7425, 7425, 2145, 132, 429, 9724, 50765, 85800, 50765, 9724, 429, 1430, 43043, 315315, 805805, 805805, 315315, 43043, 1430, 4862, 187408, 1831648, 6584032, 9962680, 6584032, 1831648, 187408, 4862, 16796, 806208, 10127988, 48674808, 103698504, 103698504, 48674808, 10127988, 806208, 16796
Offset: 0
The first few antidiagonals are:
1,
2, 2,
5, 16, 5,
14, 91, 91, 14,
42, 456, 936, 456, 42,
132, 2145, 7425, 7425, 2145, 132,
...
The first row and column of the array are the Catalan numbers
A000108.
The second row and column are
A214824.
-
a[x_, y_] := (2(2x+2y+1)!(x^2+3x*y+y^2+4x+4y+3)) / (x!(x+1)!y!(y+1)!(x+y+1)(x+y+2)(x+y+3));
Table[Table[a[x-y, y], {y, 0, x}] // Reverse, {x, 0, 9}] // Flatten (* Jean-François Alcover, Aug 11 2017 *)
A356367
Number of plane partitions of n having exactly one row and one column, each of equal length.
Original entry on oeis.org
1, 1, 1, 2, 2, 5, 6, 11, 16, 26, 36, 58, 81, 122, 172, 251, 350, 502, 692, 972, 1332, 1842, 2499, 3414, 4592, 6200, 8277, 11064, 14656, 19424, 25544, 33584, 43880, 57274, 74362, 96429, 124468, 160422, 205942, 263938, 337083, 429768
Offset: 0
For n = 7 the valid unimodal compositions of n+1=8 are (8), (1,6,1), (1,5,2), (2,5,1), (3,4,1), (1,4,3), (2,4,2), (1,1,4,1,1), (1,1,3,2,1), (1,2,3,1,1) and (1,1,1,2,1,1,1), and so a(7) = 11.
-
nmax = 50; CoefficientList[Series[1 + 1/Product[(1 - x^k)^2, {k, 1, nmax}] * Sum[(-1)^(k + r + 1) * x^(k*(k + 1)/2 + r*(r + 1)/2 + 2*k*r)*(1 - x^r), {r, 0, nmax}, {k, 0, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 28 2023 *)
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