A158830 Triangle, read by rows n>=1, where row n is the n-th differences of column n of array A158825, where the g.f. of row n of A158825 is the n-th iteration of x*Catalan(x).
1, 1, 0, 2, 0, 0, 5, 1, 0, 0, 14, 10, 0, 0, 0, 42, 70, 8, 0, 0, 0, 132, 424, 160, 4, 0, 0, 0, 429, 2382, 1978, 250, 1, 0, 0, 0, 1430, 12804, 19508, 6276, 302, 0, 0, 0, 0, 4862, 66946, 168608, 106492, 15674, 298, 0, 0, 0, 0, 16796, 343772, 1337684, 1445208, 451948
Offset: 1
Examples
Triangle begins: .1; .1,0; .2,0,0; .5,1,0,0; .14,10,0,0,0; .42,70,8,0,0,0; .132,424,160,4,0,0,0; .429,2382,1978,250,1,0,0,0; .1430,12804,19508,6276,302,0,0,0,0; .4862,66946,168608,106492,15674,298,0,0,0,0; .16796,343772,1337684,1445208,451948,33148,244,0,0,0,0; .58786,1744314,10003422,16974314,9459090,1614906,61806,162,0,0,0,0; .208012,8780912,71692452,180308420,161380816,51436848,5090124,103932,84,0,0,0,0; .... where the g.f. of row n is (1-x)^n*[g.f. of column n of A158825]; g.f. of row n of array A158825 is the n-th iteration of x*C(x): .1,1,2,5,14,42,132,429,1430,4862,16796,58786,208012,742900,...; .1,2,6,21,80,322,1348,5814,25674,115566,528528,2449746,...; .1,3,12,54,260,1310,6824,36478,199094,1105478,6227712,...; .1,4,20,110,640,3870,24084,153306,993978,6544242,43652340,...; .1,5,30,195,1330,9380,67844,500619,3755156,28558484,...; .1,6,42,315,2464,19852,163576,1372196,11682348,100707972,...; .1,7,56,476,4200,38052,351792,3305484,31478628,303208212,...; .1,8,72,684,6720,67620,693048,7209036,75915708,807845676,...; .... ROW-REVERSAL yields triangle A122890: .1; .0,1; .0,0,2; .0,0,1,5; .0,0,0,10,14; .0,0,0,8,70,42; .0,0,0,4,160,424,132; .0,0,0,1,250,1978,2382,429; .0,0,0,0,302,6276,19508,12804,1430; ... where g.f. of row n = (1-x)^n*[g.f. of column n of A122888]; g.f. of row n of A122888 is the n-th iteration of x+x^2: .1; .1,1; .1,2,2,1; .1,3,6,9,10,8,4,1; .1,4,12,30,64,118,188,258,302,298,244,162,84,32,8,1; ...
Links
- Paul D. Hanna, Table of n, a(n), n = 1..1326 (rows 1..51).
- Toufik Mansour, Howard Skogman, Rebecca Smith, Passing through a stack k times, arXiv:1704.04288 [math.CO], 2017.
Programs
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Mathematica
nmax = 11; f[0][x_] := x; f[n_][x_] := f[n][x] = f[n - 1][x + x^2] // Expand; T = Table[SeriesCoefficient[f[n][x], {x, 0, k}], {n, 0, nmax}, {k, 1, nmax}]; row[n_] := CoefficientList[(1-x)^n*(T[[All, n]].x^Range[0, nmax])+O[x]^nmax, x] // Reverse; Table[row[n], {n, 1, nmax}] // Flatten (* Jean-François Alcover, Oct 26 2018 *)
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PARI
{T(n, k)=local(F=x, CAT=serreverse(x-x^2+x*O(x^(n+2))), M, N, P); M=matrix(n+2, n+2, r, c, F=x; for(i=1, r, F=subst(F, x, CAT)); polcoeff(F, c)); Vec(truncate(Ser(vector(n+1,r,M[r,n+1])))*(1-x)^(n+1) +x*O(x^k))[k+1]}
Formula
Extensions
Edited by N. J. A. Sloane, Oct 04 2010, to make entries, offset, b-file and link to b-file all consistent.