A330801
a(n) = A080247(2*n, n), the central values of the Big-Schröder triangle.
Original entry on oeis.org
1, 4, 30, 264, 2490, 24396, 244790, 2496528, 25763058, 268243860, 2812481870, 29653804824, 314097641130, 3339741725404, 35626286189670, 381098437754912, 4086504567333858, 43912100376527652, 472743964145437310, 5097853987059017000, 55054474579787825562
Offset: 0
-
A330801:= func< n | ((n+1)/(2*n+1))*(&+[Binomial(2*n+1, n+j+1)*Binomial(2*n+j, j): j in [0..n]]) >;
[A330801(n): n in [0..40]]; // G. C. Greubel, May 03 2023
-
a := n -> ((n+1)/(2*n+1))*binomial(2*n+1, n+1)*hypergeom([-n, 2*n+1], [n+2], -1):
seq(simplify(a(n)), n=0..20);
# Alternative:
alias(C = binomial):
a := n -> ((n+1)/(2*n+1))*add(C(2*n+1, n+j+1)*C(2*n+j, j), j=0..n):
seq(a(n), n=0..20);
-
a[n_]:= (1/Sqrt[Pi]) 4^n (1 + n) Gamma[1/2 + n] Hypergeometric2F1Regularized[-n, 1 + 2 n, 2 + n, -1]; Table[a[n], {n, 0, 20}]
-
def A330801(n) -> int:
s = sum( binomial(2 * n + 1, n + j + 1) * binomial(2 * n + j, j)
for j in range(n + 1) )
return (s * (n + 1)) // (2 * n + 1)
print([A330801(n) for n in range(41)]) # G. C. Greubel, May 03 2023
A033877
Triangular array read by rows associated with Schroeder numbers: T(1,k) = 1; T(n,k) = 0 if k < n; T(n,k) = T(n,k-1) + T(n-1,k-1) + T(n-1,k).
Original entry on oeis.org
1, 1, 2, 1, 4, 6, 1, 6, 16, 22, 1, 8, 30, 68, 90, 1, 10, 48, 146, 304, 394, 1, 12, 70, 264, 714, 1412, 1806, 1, 14, 96, 430, 1408, 3534, 6752, 8558, 1, 16, 126, 652, 2490, 7432, 17718, 33028, 41586, 1, 18, 160, 938, 4080, 14002, 39152, 89898, 164512, 206098
Offset: 1
Triangle starts:
1;
1, 2;
1, 4, 6;
1, 6, 16, 22;
1, 8, 30, 68, 90;
1, 10, 48, 146, 304, 394;
1, 12, 70, 264, 714, 1412, 1806;
... - _Joerg Arndt_, Sep 29 2013
- T. D. Noe, Rows k = 1..50 of triangle, flattened
- Henry Bottomley, Illustration of initial terms
- Kevin Brown, Hipparchus on Compound Statements, 1994-2010. - _Johannes W. Meijer_, Sep 22 2010
- James East and Nicholas Ham, Lattice paths and submonoids of Z^2, arXiv:1811.05735 [math.CO], 2018.
- G. Kreweras, Sur les hiérarchies de segments, Cahiers Bureau Universitaire Recherche Opérationnelle, Cahier 20, Inst. Statistiques, Univ. Paris, 1973.
- G. Kreweras, Sur les hiérarchies de segments, Cahiers du Bureau Universitaire de Recherche Opérationnelle, Institut de Statistique, Université de Paris, #20 (1973). (Annotated scanned copy)
- G. Kreweras, Aires des chemins surdiagonaux et application à un problème économique, Cahiers du Bureau universitaire de recherche opérationnelle Série Recherche 24 (1976): 1-8. [Annotated scanned copy]
- J. W. Meijer, Famous numbers on a chessboard, Acta Nova, Volume 4, No.4, December 2010. pp. 589-598.
- J. M. Oh, An explicit formula for the number of fuzzy subgroups of a finite abelian p-group of rank two, Iranian Journal of Fuzzy Systems, Dec 2013, Vol. 10 Issue 6, pp. 125-135.
- E. Pergola and R. A. Sulanke, Schroeder Triangles, Paths and Parallelogram Polyominoes, J. Integer Sequences, 1 (1998), #98.1.7.
- S. Samieinia, The number of continuous curves in digital geometry, Port. Math. 67 (1) (2010) 75-89, last table.
- R. A. Sulanke, Objects counted by the central Delannoy numbers, J. Integer Seq. 6 (2003), Article 03.1.5, 19 pp.
- Luis Verde-Star, A Matrix Approach to Generalized Delannoy and Schröder Arrays, J. Int. Seq., Vol. 24 (2021), Article 21.4.1.
Essentially same triangle as
A080247 and
A080245 but with rows read in reversed order. Also essentially the same triangle as
A106579.
Triangle sums (see the comments):
A001003 (Row1, Row2),
A026003 (Kn1p, p >= 1),
A006603 (Kn21),
A227504 (Kn22),
A227505 (Kn23),
A006603(2*n) (Kn3),
A001850 (Kn4),
A227506 (Fi1),
A010683 (Fi2).
-
a033877 n k = a033877_tabl !! n !! k
a033877_row n = a033877_tabl !! n
a033877_tabl = iterate
(\row -> scanl1 (+) $ zipWith (+) ([0] ++ row) (row ++ [0])) [1]
-- Reinhard Zumkeller, Apr 17 2013
-
function t(n,k)
if k le 0 or k gt n then return 0;
elif k eq 1 then return 1;
else return t(n,k-1) + t(n-1,k-1) + t(n-1,k);
end if;
end function;
[t(n,k): k in [1..n], n in [1..12]]; // G. C. Greubel, Mar 23 2023
-
T := proc(n, k) option remember; if n=1 then return(1) fi; if kJohannes W. Meijer, Sep 22 2010, revised Jul 17 2013
-
T[1, ]:= 1; T[n, k_]/;(k
-
def A033877_row(n):
@cached_function
def prec(n, k):
if k==n: return 1
if k==0: return 0
return prec(n-1,k-1)-2*sum(prec(n,k+i-1) for i in (2..n-k+1))
return [(-1)^k*prec(n, n-k) for k in (0..n-1)]
for n in (1..10): print(A033877_row(n)) # Peter Luschny, Mar 16 2016
-
@CachedFunction
def t(n, k): # t = A033847
if (k<0 or k>n): return 0
elif (k==1): return 1
else: return t(n, k-1) + t(n-1, k-1) + t(n-1, k)
flatten([[t(n,k) for k in range(1,n+1)] for n in range(1, 16)]) # G. C. Greubel, Mar 23 2023
Original entry on oeis.org
1, -2, 1, 2, -4, 1, -2, 8, -6, 1, 2, -12, 18, -8, 1, -2, 16, -38, 32, -10, 1, 2, -20, 66, -88, 50, -12, 1, -2, 24, -102, 192, -170, 72, -14, 1, 2, -28, 146, -360, 450, -292, 98, -16, 1, -2, 32, -198, 608, -1002, 912, -462, 128, -18, 1, 2, -36, 258, -952, 1970, -2364
Offset: 0
Rows are {1}, {-2,1}, {2,-4,1}, {-2,8,-6,1}, ...
A330802
Evaluation of the Big-Schröder polynomials at 1/2 and normalized with 2^n.
Original entry on oeis.org
1, 5, 33, 253, 2121, 18853, 174609, 1667021, 16290969, 162171445, 1638732129, 16765758429, 173325794409, 1807840791237, 19001320087473, 201050792435949, 2139811906460985, 22892988893079637, 246061004607915777, 2655768423781296893, 28771902274699214601
Offset: 0
-
a := proc(n) option remember; if n < 3 then return [1, 5, 33][n+1] fi;
((24 - 12*n)*a(n-3) + (32*n - 10)*a(n-2) + (9*n - 9)*a(n-1))/(n+1) end:
seq(a(n), n=0..20);
# Alternative:
gf := 2/(1 - 4*x + sqrt(1 + 4*(x - 3)*x)):
ser := series(gf, x, 24):
seq(coeff(ser, x, n), n=0..20);
# Or:
series((x - x^2)/(3*x^2 + 4*x + 1), x, 24):
gfun:-seriestoseries(%, 'revogf'):
convert(%, polynom) / x: seq(coeff(%, x, n), n=0..20);
-
A080247[n_, k_] := (k+1)*Sum[2^m*Binomial[n+1, m]*Binomial[n-k-1, n-k-m], {m, 0, n-k}]/(n+1);
a[n_] := 2^n*Sum[A080247[n, k]/2^k , {k, 0, n}];
Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Oct 22 2023 *)
-
N=20; x='x+O('x^N); Vec(2/(1-4*x+sqrt(1+4*(x-3)*x))) \\ Seiichi Manyama, Feb 03 2020
-
R. = PowerSeriesRing(QQ)
f = (x - x^2)/(3*x^2 + 4*x + 1)
f.reverse().shift(-1).list()
A330803
Evaluation of the Big-Schröder polynomials at -1/2 and normalized with (-2)^n.
Original entry on oeis.org
1, -3, 17, -123, 1001, -8739, 79969, -756939, 7349657, -72798003, 732681489, -7471545435, 77031538377, -801616570947, 8408819677377, -88821190791915, 943928491520249, -10085451034660947, 108275140773938545, -1167408859459660923, 12635538801834255401
Offset: 0
-
a := proc(n) option remember; if n < 3 then return [1, -3, 17][n+1] fi;
((8 - 4*n)*a(n-3) + (30 - 24*n)*a(n-2) + (17 - 37*n)*a(n-1))/(3*n + 3) end:
seq(a(n), n=0..20);
# Alternative:
gf := 2/(1 + sqrt(1 + 4*x*(x + 3))):
ser := series(gf, x, 24):
seq(coeff(ser, x, n), n=0..20);
# Or:
series((3*x^2 + x)/(1 - x^2), x, 24):
gfun:-seriestoseries(%, 'revogf'):
convert(%, polynom) / x: seq(coeff(%, x, n), n=0..20);
-
N=20; x='x+O('x^N); Vec(2/(1+sqrt(1+4*x*(x+3)))) \\ Seiichi Manyama, Feb 03 2020
-
R. = PowerSeriesRing(QQ)
f = (3*x^2 + x)/(1 - x^2)
f.reverse().shift(-1).list()
A122538
Riordan array (1, x*f(x)) where f(x)is the g.f. of A006318.
Original entry on oeis.org
1, 0, 1, 0, 2, 1, 0, 6, 4, 1, 0, 22, 16, 6, 1, 0, 90, 68, 30, 8, 1, 0, 394, 304, 146, 48, 10, 1, 0, 1806, 1412, 714, 264, 70, 12, 1, 0, 8558, 6752, 3534, 1408, 430, 96, 14, 1, 0, 41586, 33028, 17718, 7432, 2490, 652, 126, 16, 1, 0, 206098, 164512, 89898, 39152, 14002, 4080, 938, 160, 18, 1
Offset: 0
Triangle begins:
1;
0, 1:
0, 2, 1;
0, 6, 4, 1;
0, 22, 16, 6, 1;
0, 90, 68, 30, 8, 1;
0, 394, 304, 146, 48, 10, 1;
0, 1806, 1412, 714, 264, 70, 12, 1;
0, 8558, 6752, 3534, 1408, 430, 96, 14, 1;
Production matrix is:
0...1
0...2...1
0...2...2...1
0...2...2...2...1
0...2...2...2...2...1
0...2...2...2...2...2...1
0...2...2...2...2...2...2...1
0...2...2...2...2...2...2...2...1
0...2...2...2...2...2...2...2...2...1
... - _Philippe Deléham_, Feb 09 2014
-
function T(n,k) // T = A122538
if k eq 0 then return 0^n;
elif k eq n then return 1;
else return T(n-1,k-1) + T(n-1,k) + T(n,k+1);
end if;
end function;
[T(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, Oct 27 2024
-
T[n_, n_]= 1; T[, 0]= 0; T[n, k_]:= T[n, k]= T[n-1, k-1] + T[n-1, k] + T[n, k+1];
Table[T[n,k], {n,0,12}, {k,0,n}]//Flatten (* Jean-François Alcover, Jun 13 2019 *)
-
def A122538_row(n):
@cached_function
def prec(n, k):
if k==n: return 1
if k==0: return 0
return prec(n-1,k-1)-2*sum(prec(n,k+i-1) for i in (2..n-k+1))
return [(-1)^(n-k)*prec(n, k) for k in (0..n)]
for n in (0..12): print(A122538_row(n)) # Peter Luschny, Mar 16 2016
A183875
Triangle T(n,k) for A(x)^k=sum(n>=k T(n,k)*x^n), where o.g.f. A(x) satisfies A(x)=(a+b*x*A(x))/(c-d*x*A(x)), a=1,b=2,c=1,d=2.
Original entry on oeis.org
1, 4, 1, 24, 8, 1, 176, 64, 12, 1, 1440, 544, 120, 16, 1, 12608, 4864, 1168, 192, 20, 1, 115584, 45184, 11424, 2112, 280, 24, 1, 1095424, 432128, 113088, 22528, 3440, 384, 28, 1, 10646016, 4227584, 1133952, 237824, 39840, 5216, 504, 32, 1, 105522176, 42115072, 11506944, 2505728, 448064, 65280, 7504, 640, 36, 1
Offset: 1
1,
4,1,
24,8,1,
176,64,12,1,
1440,544,120,16,1,
12608,4864,1168,192,20,1,
115584,45184,11424,2112,280,24,1,
1095424,432128,113088,22528,3440,384,28,1,
10646016,4227584,1133952,237824,39840,5216,504,32,1,
105522176,42115072,11506944,2505728,448064,65280,7504,640,36,1
-
T[n_, k_, a_, b_, c_, d_] := k/n Sum[Binomial[n, n - k - i] a^(k + i) b^(n - k - i) Binomial[i + n - 1, n - 1] c^(-i - n) d^i, {i, 0, n - k}];
T[n_, k_] := T[n, k, 1, 2, 1, 2];
Table[T[n, k], {n, 1, 10}, {k, 1, n}] // Flatten (* Jean-François Alcover, Aug 08 2018, from formula *)
Showing 1-7 of 7 results.
Comments