cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-8 of 8 results.

A025757 4th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 7, 69, 783, 9597, 123495, 1643397, 22413183, 311466829, 4392857431, 62702224213, 903886452975, 13138698859677, 192337495360071, 2832859169364261, 41946319269028191, 624009420903043821
Offset: 0

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Crossrefs

a(n), n >= 1, = row sums of triangle A049213.

Programs

  • Mathematica
    Table[SeriesCoefficient[4/(3 + (1 - 16*x)^(1/4)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)

Formula

G.f.: 4 / (3+(1-16*x)^(1/4)).
a(n) = Sum_{m=1..n-1} (m/n*4^(n-m)) * Sum_{k=1..n-m} binomial(n+k-1,n-1) * Sum_{j=0..k} binomial(j,n-m-3*k+2*j) * 4^(j-k) * binomial(k,j) * 3^(-n+m+3*k-j) * 2^(n-m-3*k+j) * (-1)^(n-m-3*k+2*j) + 1. - Vladimir Kruchinin, Feb 08 2011
Conjecture: 5*n*(n-1)*(n-2)*a(n) -(239*n-600)*(n-1)*(n-2)*a(n-1) +24*(n-2)*(158*n^2-953*n+1445)*a(n-2) +16*(-1232*n^3+13056*n^2-45949*n+53730)*a(n-3) -128*(4*n-15)*(2*n-7)*(4*n-13)*a(n-4)=0. - R. J. Mathar, Jul 28 2014
a(n) = (-1)^(n+1) * 4^(2*n+1) * Sum_{k>=0} (-1/3)^(k+1) * binomial(k/4,n). - Seiichi Manyama, Aug 04 2024

A025758 5th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 11, 171, 3056, 58916, 1191376, 24896436, 532911346, 11617952106, 256966100966, 5750337968926, 129926216608236, 2959472057112396, 67877180959091156, 1566072624078270516, 36319953436423545851
Offset: 0

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a(n), n >= 1, = row sums of triangle A049223.

Programs

  • Maple
    # Based on Tani Akinari's formula.
    h := (n,j) -> ((-1)^n/(-4)^j)*binomial(j/5,n+1)*hypergeom([1,n+1-j/5],[n+2], 1025): a := n -> 2^8*5^(2*n+1)*add(h(n,j), j=1..4):
    seq(round(evalf(a(n),64)),n=0..16); # Peter Luschny, Sep 21 2015
  • Mathematica
    Table[SeriesCoefficient[5/(4 + (1 - 25*x)^(1/5)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)
  • Maxima
    a(n):=(256/205)*41^(-n)*sum(sum((-4)^(-k)*(-1025)^m*binomial(k/5,m),k,0,4),m,0,n);  /* Tani Akinari, Sep 16 2015  */

Formula

G.f.: 5 / (4+(1-25*x)^(1/5)).
a(n) = sum(m=1..n-1, 5^(n-m)*m/n * sum(k=1..n-m, binomial(n+k-1,n-1) * sum(i=0..k, binomial(k,i) * 2^(k-i) * sum(j=0..i, binomial(j,-3*i+n-m-k+2*j) * (-1)^(j-i)*5^(j-i)*(-2)^(3*i-n+m+k-j) * binomial(i,j)))))+1. - Vladimir Kruchinin, Feb 09 2011
Conjecture: 41*n*(n-1)*(n-2)*(n-3)*a(n) -3*(1367*n-4100)*(n-1)*(n-2)*(n-3)*a(n-1) +50*(n-2)*(n-3)*(3077*n^2-21533*n+38136)*a(n-2) -250*(n-3)*(10265*n^3-123135*n^2+494446*n-664572)*a(n-3) +1875*(8575*n^4-154250*n^3+1039765*n^2-3112730*n+3491808)*a(n-4) -625*(5*n-22)*(5*n-21)*(5*n-24)*(5*n-23)*a(n-5)=0. - R. J. Mathar, Jul 28 2014
a(n) = (-1)^(n+1) * 5^(2*n+1) * Sum_{k>=0} (-1/4)^(k+1) * binomial(k/5,n). - Seiichi Manyama, Aug 04 2024

A025759 6th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 16, 361, 9346, 260710, 7622290, 230167345, 7116228250, 224012186830, 7152402830440, 230999414308090, 7531444277855740, 247510726140787240, 8189274963276187990, 272537576338530727585, 9116110475685684958810, 306286229879232067776310
Offset: 0

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Crossrefs

a(n), n >= 1, = row sums of triangle A049224.

Programs

  • Mathematica
    Table[SeriesCoefficient[6/(5 + (1 - 36*x)^(1/6)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)
  • Maxima
    a[0]:1$ a[1]:1$ a[2]:16$ a[3]:361$ a[4]:9346$ a[5]:260710$
    a[n]:=((n-1)*(n-2)*(n-3)*(n-4)*(78119*n-273420)*a[n-1]-90*(n-2)*(n-3)*(n-4)*(62494*n^2-499959*n+1014685)*a[n-2]+180*(n-3)*(n-4)*(1124856*n^3-15185808*n^2+68852647*n-104826890)*a[n-3]-3240*(n-4)*(1124784*n^4-22496184*n^3+169193274*n^2-567111339*n+714764687)*a[n-4]+5184*(5060556*n^5-139170960*n^4+1530231885*n^3-8408803050*n^2+23092951859*n-25356134300)*a[n-5]+93312*(2*n-11)*(3*n-16)*(3*n-17)*(6*n-31)*(6*n-35)*a[n-6])/(434*n*(n-1)*(n-2)*(n-3)*(n-4));
    makelist(a[n],n,0,500);  /* Tani Akinari, Sep 15 2015  */
    
  • PARI
    default(seriesprecision, 40); Vec(6/(5+(1-36*x)^(1/6)) + O(x^30)) \\ Michel Marcus, Sep 15 2015

Formula

G.f.: 6/(5+(1-36*x)^(1/6)).
Recurrence: for n>5,
a(n)=((n-1)*(n-2)*(n-3)*(n-4)*(78119*n-273420)*a(n-1)-90*(n-2)*(n-3)*(n-4)*(62494*n^2-499959*n+1014685)*a(n-2)+180*(n-3)*(n-4)*(1124856*n^3-15185808*n^2+68852647*n-104826890)*a(n-3)-3240*(n-4)*(1124784*n^4-22496184*n^3+169193274*n^2-567111339*n+714764687)*a(n-4)+5184*(5060556*n^5-139170960*n^4+1530231885*n^3-8408803050*n^2+23092951859*n-25356134300)*a(n-5)+93312*(2*n-11)*(3*n-16)*(3*n-17)*(6*n-31)*(6*n-35)*a(n-6))/(434*n*(n-1)*(n-2)*(n-3)*(n-4)). - Tani Akinari, Sep 15 2015
a(n) ~ 36^n / (25 * Gamma(5/6) * n^(7/6)) * (1 - 2^(1/3)*sqrt(3)*Gamma(2/3) / (5*sqrt(Pi)*n^(1/6))). - Vaclav Kotesovec, Sep 22 2015
a(n) = (-1)^(n+1) * 6^(2*n+1) * Sum_{k>=0} (-1/5)^(k+1) * binomial(k/6,n). - Seiichi Manyama, Aug 04 2024

A025760 7th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 22, 680, 24074, 917414, 36618492, 1508943612, 63643109727, 2732349490669, 118957846271104, 5237911268468572, 232794783971436296, 10427673857731312064, 470213556090357498728, 21325335129901497816528
Offset: 0

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Programs

  • Mathematica
    Table[SeriesCoefficient[7/(6 + (1 - 49*x)^(1/7)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)

Formula

G.f.: 7/(6 + (1 - 49*x)^(1/7)).
a(n) = (-1)^(n+1) * 7^(2*n+1) * Sum_{k>=0} (-1/6)^(k+1) * binomial(k/7,n). - Seiichi Manyama, Aug 04 2024

A025761 8th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 29, 1177, 54629, 2726977, 142504685, 7685245225, 424109499317, 23818681210961, 1356315674712509, 78100982458201017, 4538960021319997189, 265837773438037013857, 15672475449746510425485
Offset: 0

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Programs

  • Mathematica
    Table[SeriesCoefficient[8/(7 + (1 - 64 x)^(1/8)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)
    CoefficientList[Series[8/(7+Surd[1-64x,8]),{x,0,20}],x] (* Harvey P. Dale, Jun 19 2022 *)

Formula

G.f.: 8/(7 + (1 - 64*x)^(1/8)).
a(n) = (-1)^(n+1) * 8^(2*n+1) * Sum_{k>=0} (-1/7)^(k+1) * binomial(k/8,n). - Seiichi Manyama, Aug 04 2024

A025762 9th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 37, 1909, 112483, 7123123, 472012183, 32269160215, 2256940619488, 160620490138312, 11588554266307408, 845405636848547320, 62239772654736987376, 4617428134374127211320, 344799253687326693132448
Offset: 0

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Programs

  • Mathematica
    Table[SeriesCoefficient[9/(8 + (1 - 81 x)^(1/9)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)

Formula

G.f.: 9/(8 + (1 - 81*x)^(1/9)).
a(n) = (-1)^(n+1) * 9^(2*n+1) * Sum_{k>=0} (-1/8)^(k+1) * binomial(k/9,n). - Seiichi Manyama, Aug 04 2024

A025763 10th-order Vatalan numbers (generalization of Catalan numbers).

Original entry on oeis.org

1, 1, 46, 2941, 214486, 16801306, 1376657776, 116346220021, 10057692309166, 884572748725086, 78862377561315156, 7108473985655908626, 646575307673212875996, 59260508917444358016516
Offset: 0

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Programs

  • Mathematica
    Table[SeriesCoefficient[10/(9 + (1 - 100 x)^(1/10)), {x, 0, n}], {n, 0, 20}] (* Vincenzo Librandi, Dec 29 2012 *)
    CoefficientList[Series[10/(9+Surd[1-100x,10]),{x,0,20}],x] (* Harvey P. Dale, Feb 12 2017 *)

Formula

G.f.: 10/(9 + (1 - 100*x)^(1/10)).
a(n) = (-1)^(n+1) * 10^(2*n+1) * Sum_{k>=0} (-1/9)^(k+1) * binomial(k/10,n). - Seiichi Manyama, Aug 04 2024

A048966 A convolution triangle of numbers obtained from A025748.

Original entry on oeis.org

1, 3, 1, 15, 6, 1, 90, 39, 9, 1, 594, 270, 72, 12, 1, 4158, 1953, 567, 114, 15, 1, 30294, 14580, 4482, 1008, 165, 18, 1, 227205, 111456, 35721, 8667, 1620, 225, 21, 1, 1741905, 867834, 287199, 73656, 15075, 2430, 294, 24, 1, 13586859, 6857136, 2328183, 623106, 136323, 24354, 3465, 372, 27, 1
Offset: 1

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Comments

A generalization of the Catalan triangle A033184.

Examples

			Triangle begins:
     1;
     3,    1;
    15,    6,    1;
    90,   39,    9,    1;
   594,  270,   72,   12,    1;
  4158, 1953,  567,  114,   15,    1;
		

Crossrefs

Cf. A034000, A049213, A049223, A049224. a(n, 1)= A025748(n), a(n, 1)= 3^(n-1)*2*A034000(n-1)/n!, n >= 2. Row sums = A025756.

Programs

  • Haskell
    a048966 n k = a048966_tabl !! (n-1) !! (k-1)
    a048966_row n = a048966_tabl !! (n-1)
    a048966_tabl = [1] : f 2 [1] where
       f x xs = ys : f (x + 1) ys where
         ys = map (flip div x) $ zipWith (+)
              (map (* 3) $ zipWith (*) (map (3 * (x - 1) -) [1..]) (xs ++ [0]))
              (zipWith (*) [1..] ([0] ++ xs))
    -- Reinhard Zumkeller, Feb 19 2014
  • Mathematica
    a[n_, m_] /; n >= m >= 1 := a[n, m] = 3*(3*(n-1) - m)*a[n-1, m]/n + m*a[n-1, m-1]/n; a[n_, m_] /; n < m := 0; a[n_, 0] = 0; a[1, 1] = 1; Table[a[n, m], {n, 1, 10}, {m, 1, n}] // Flatten (* Jean-François Alcover, Apr 26 2011, after given formula *)

Formula

a(n, m) = 3*(3*(n-1)-m)*a(n-1, m)/n + m*a(n-1, m-1)/n, n >= m >= 1; a(n, m) := 0, n
G.f. for m-th column: ((1-(1-9*x)^(1/3))/3)^m.
a(n,m) = m/n * sum(k=0..n-m, binomial(k,n-m-k) * 3^k*(-1)^(n-m-k) * binomial(n+k-1,n-1)). - Vladimir Kruchinin, Feb 08 2011
Showing 1-8 of 8 results.