cp's OEIS Frontend

A014138 Partial sums of (Catalan numbers starting 1, 2, 5, ...).

%I A014138 #149 Dec 30 2024 04:17:38
%S A014138 0,1,3,8,22,64,196,625,2055,6917,23713,82499,290511,1033411,3707851,
%T A014138 13402696,48760366,178405156,656043856,2423307046,8987427466,
%U A014138 33453694486,124936258126,467995871776,1757900019100
%N A014138 Partial sums of (Catalan numbers starting 1, 2, 5, ...).
%C A014138 Number of paths starting from the root in all ordered trees with n+1 edges (a path is a nonempty tree with no vertices of outdegree greater than 1). Example: a(2)=8 because the five trees with three edges have altogether 1+0+2+2+3=8 paths hanging from the roots. - _Emeric Deutsch_, Oct 20 2002
%C A014138 a(n) is the sum of the mean maximal pyramid size over all Dyck (n+1)-paths. Also, a(n) = sum of the mean maximal sawtooth size over all Dyck (n+1)-paths. A pyramid (resp. sawtooth) in a Dyck path is a subpath of the form U^k D^k (resp. (UD)^k) with k>=1 and k is its size. For example, the maximal pyramids in the Dyck path uUUDD|UD|UDdUUDD are indicated by uppercase letters (and separated by a vertical bar). Their sizes are 2,1,1,2 left to right and the mean maximal pyramid size of the path is 6/4 = 3/2. Also, the mean maximal sawtooth size of this path is (1+2+1)/3 = 4/3. - _David Callan_, Jun 07 2006
%C A014138 p^2 divides a(p-1) for prime p of form p=6k+1 (A002476(k)). - _Alexander Adamchuk_, Jul 03 2006
%C A014138 p^2 divides a(p^2-1) for prime p>3. p^2 divides a(p^3-1) for prime p=7,13,19,... prime p in the form p=6k+1. - _Alexander Adamchuk_, Jul 03 2006
%C A014138 Row sums of triangle A137614. - _Gary W. Adamson_, Jan 30 2008
%C A014138 Equals INVERTi transform of A095930: (1, 4, 15, 57, 220, 859, ...). - _Gary W. Adamson_, May 15 2009
%C A014138 a(n) < A000108(n+1), therefore A176137(n) <= 1. - _Reinhard Zumkeller_, Apr 10 2010
%C A014138 a(n) is also the sum of the numbers in Catalan's triangle (A009766) from row 0 to row n. - _Patrick Labarque_, Jul 27 2010
%C A014138 Equals the Catalan sequence starting (1, 1, 2, ...) convolved with A014137 starting (1, 2, 4, 9, ...). - _Gary W. Adamson_, May 20 2013
%C A014138 p divides a((p-3)/2) for primes {11,23,47,59,...} = A068231 primes congruent to 11 mod 12. - _Alexander Adamchuk_, Dec 27 2013
%C A014138 a(n) is the number of parking functions of size n avoiding the patterns 132, 213, and 231. - _Lara Pudwell_, Apr 10 2023
%H A014138 G. C. Greubel, <a href="/A014138/b014138.txt">Table of n, a(n) for n = 0..1000</a>(terms 0 to 200 computed by T. D. Noe)
%H A014138 Ayomikun Adeniran and Lara Pudwell, <a href="https://doi.org/10.54550/ECA2023V3S3R17">Pattern avoidance in parking functions</a>, Enumer. Comb. Appl. 3:3 (2023), Article S2R17.
%H A014138 Paul Barry, <a href="http://arxiv.org/abs/1107.5490">Invariant number triangles, eigentriangles and Somos-4 sequences</a>, arXiv preprint arXiv:1107.5490 [math.CO], 2011.
%H A014138 S. B. Ekhad and M. Yang, <a href="http://sites.math.rutgers.edu/~zeilberg/tokhniot/oMathar1maple12.txt">Proofs of Linear Recurrences of Coefficients of Certain Algebraic Formal Power Series Conjectured in the On-Line Encyclopedia Of Integer Sequences</a>, (2017)
%H A014138 Ângela Mestre and José Agapito, <a href="https://www.emis.de/journals/JIS/VOL22/Agapito/mestre8.html">A Family of Riordan Group Automorphisms</a>, J. Int. Seq., Vol. 22 (2019), Article 19.8.5.
%H A014138 Kevin Topley, <a href="http://arxiv.org/abs/1601.04223">Computationally Efficient Bounds for the Sum of Catalan Numbers</a>, arXiv:1601.04223 [math.CO], 2016.
%F A014138 a(n) = A014137(n)-1.
%F A014138 G.f.: (1-2*x-sqrt(1-4x))/(2x(1-x)) = (C(x)-1)/(1-x) where C(x) is the generating function for the Catalan numbers. - Rocio Blanco, Apr 02 2007
%F A014138 a(n) = Sum_{k=1..n} A000108(k). - _Alexander Adamchuk_, Jul 03 2006
%F A014138 Binomial transform of A005554: (1, 2, 3, 6, 13, 30, 72, ...). - _Gary W. Adamson_, Nov 23 2007
%F A014138 D-finite with recurrence: (n+1)*a(n) + (1-5n)*a(n-1) + 2*(2n-1)*a(n-2) = 0. - _R. J. Mathar_, Dec 14 2011
%F A014138 Equals the Catalan sequence starting (1, 1, 2, ...) convolved with A014137 starting (1, 2, 4, 9, ...). - _Gary W. Adamson_, May 20 2013
%F A014138 G.f.: 1/x - G(0)/(1-x)/x, where G(k) = 1 - x/(1 - x/(1 - x/(1 - x/G(k+1) ))); (continued fraction). - _Sergei N. Gladkovskii_, Jul 17 2013
%F A014138 G.f.: 1/x - T(0)/(2*x*(1-x)), where T(k) = 2*x*(2*k+1)+ k+2 - 2*x*(k+2)*(2*k+3)/T(k+1); (continued fraction). - _Sergei N. Gladkovskii_, Nov 27 2013
%F A014138 a(n) ~ 2^(2*n+2)/(3*sqrt(Pi)*n^(3/2)). - _Vaclav Kotesovec_, Dec 10 2013
%F A014138 a(n) = Sum_{i+j<n} C(i)*C(j), where C = A000108. - _Yuchun Ji_, Jan 10 2019
%F A014138 E.g.f.: exp(2*x)*(BesselI(0, 2*x)/2 - BesselI(1, 2*x)) + exp(x)*(3/2*Integral_{x=-oo..oo} BesselI(0,2*x)*exp(x) dx - 1/2). - _Mélika Tebni_, Aug 31 2024
%p A014138 a:=n->sum((binomial(2*j,j)/(j+1)),j=1..n): seq(a(n), n=0..24); # _Zerinvary Lajos_, Dec 01 2006
%p A014138 # Second program:
%p A014138 A014138 := series(exp(2*x)*(BesselI(0, 2*x)/2 - BesselI(1, 2*x)) + exp(x)*(3/2*int(BesselI(0, 2*x)*exp(x), x) - 1/2), x = 0, 26):
%p A014138 seq(n!*coeff(A014138, x, n), n = 0 .. 24); # _Mélika Tebni_, Aug 31 2024
%t A014138 Table[Sum[(2k)!/k!/(k+1)!,{k,1,n}],{n,1,70}] (* _Alexander Adamchuk_, Jul 03 2006 *)
%t A014138 Join[{0},Accumulate[CatalanNumber[Range[30]]]] (* _Harvey P. Dale_, Jan 25 2013 *)
%t A014138 CoefficientList[Series[(1 - 2 x - (1 - 4 x)^(1/2))/(2 x (1 - x)), {x, 0, 40}], x] (* _Vincenzo Librandi_, Jun 21 2015 *)
%t A014138 a[0] := 0; a[n_] := Sum[CatalanNumber[k], {k, 1, n}]; Table[a[n], {n,0,50}] (* _G. C. Greubel_, Jan 14 2017 *)
%o A014138 (PARI) Vec((1-2*x-(1-4*x)^(1/2))/(2*x*(1-x))) \\ _Charles R Greathouse IV_, Feb 11 2011
%o A014138 (Haskell)
%o A014138 a014138 n = a014138_list !! n
%o A014138 a014138_list = scanl1 (+) a000108_list  -- _Reinhard Zumkeller_, Mar 01 2013
%o A014138 (Python)
%o A014138 from __future__ import division
%o A014138 A014138_list, b, s = [0], 1, 0
%o A014138 for n in range(1,10**2):
%o A014138     s += b
%o A014138     A014138_list.append(s)
%o A014138     b = b*(4*n+2)//(n+2) # _Chai Wah Wu_, Jan 28 2016
%Y A014138 Cf. A000108, A002476, A005554, A068231, A095930, A137614, A155587.
%K A014138 nonn,nice
%O A014138 0,3
%A A014138 _N. J. A. Sloane_
%E A014138 Edited by _Max Alekseyev_, Sep 13 2009 (including adding an initial 0)
%E A014138 Definition edited by _N. J. A. Sloane_, Oct 03 2009