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 1-10 of 13 results. Next

A060821 Triangle read by rows. T(n, k) are the coefficients of the Hermite polynomial of order n, for 0 <= k <= n.

Original entry on oeis.org

1, 0, 2, -2, 0, 4, 0, -12, 0, 8, 12, 0, -48, 0, 16, 0, 120, 0, -160, 0, 32, -120, 0, 720, 0, -480, 0, 64, 0, -1680, 0, 3360, 0, -1344, 0, 128, 1680, 0, -13440, 0, 13440, 0, -3584, 0, 256, 0, 30240, 0, -80640, 0, 48384, 0, -9216, 0, 512, -30240, 0, 302400, 0, -403200, 0, 161280, 0, -23040, 0, 1024
Offset: 0

Views

Author

Vladeta Jovovic, Apr 30 2001

Keywords

Comments

Exponential Riordan array [exp(-x^2), 2x]. - Paul Barry, Jan 22 2009

Examples

			[1], [0, 2], [ -2, 0, 4], [0, -12, 0, 8], [12, 0, -48, 0, 16], [0, 120, 0, -160, 0, 32], ... .
Thus H_0(x) = 1, H_1(x) = 2*x, H_2(x) = -2 + 4*x^2, H_3(x) = -12*x + 8*x^3, H_4(x) = 12 - 48*x^2 + 16*x^4, ...
Triangle starts:
     1;
     0,     2;
    -2,     0,      4;
     0,   -12,      0,      8;
    12,     0,    -48,      0,      16;
     0,   120,      0,   -160,       0,    32;
  -120,     0,    720,      0,    -480,     0,     64;
     0, -1680,      0,   3360,       0, -1344,      0,   128;
  1680,     0, -13440,      0,   13440,     0,  -3584,     0,    256;
     0, 30240,      0, -80640,       0, 48384,      0, -9216,      0, 512;
-30240,     0, 302400,      0, -403200,     0, 161280,     0, -23040,   0, 1024;
		

References

  • Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 24, equations 24:4:1 - 24:4:8 at page 219.

Crossrefs

Cf. A001814, A001816, A000321, A062267 (row sums).
Without initial zeros, same as A059343.

Programs

  • Maple
    with(orthopoly):for n from 0 to 10 do H(n,x):od;
    T := proc(n,m) if n-m >= 0 and n-m mod 2 = 0 then ((-1)^((n-m)/2))*(2^m)*n!/(m!*((n-m)/2)!) else 0 fi; end;
    # Alternative:
    T := proc(n,k) option remember; if k > n then 0 elif n = k then 2^n else
    (T(n, k+2)*(k+2)*(k+1))/(2*(k-n)) fi end:
    seq(print(seq(T(n, k), k = 0..n)), n = 0..10); # Peter Luschny, Jan 08 2023
  • Mathematica
    Flatten[ Table[ CoefficientList[ HermiteH[n, x], x], {n, 0, 10}]] (* Jean-François Alcover, Jan 18 2012 *)
  • PARI
    for(n=0,9,v=Vec(polhermite(n));forstep(i=n+1,1,-1,print1(v[i]", "))) \\ Charles R Greathouse IV, Jun 20 2012
    
  • Python
    from sympy import hermite, Poly, symbols
    x = symbols('x')
    def a(n): return Poly(hermite(n, x), x).all_coeffs()[::-1]
    for n in range(21): print(a(n)) # Indranil Ghosh, May 26 2017
    
  • Python
    def Trow(n: int) -> list[int]:
        row: list[int] = [0] * (n + 1); row[n] = 2**n
        for k in range(n - 2, -1, -2):
            row[k] = -(row[k + 2] * (k + 2) * (k + 1)) // (2 * (n - k))
        return row  # Peter Luschny, Jan 08 2023

Formula

T(n, k) = ((-1)^((n-k)/2))*(2^k)*n!/(k!*((n-k)/2)!) if n-k is even and >= 0, else 0.
E.g.f.: exp(-y^2 + 2*y*x).
From Paul Barry, Aug 28 2005: (Start)
T(n, k) = n!/(k!*2^((n-k)/2)((n-k)/2)!)2^((n+k)/2)cos(Pi*(n-k)/2)(1 + (-1)^(n+k))/2;
T(n, k) = A001498((n+k)/2, (n-k)/2)*cos(Pi*(n-k)/2)2^((n+k)/2)(1 + (-1)^(n+k))/2.
(End)
Row sums: A062267. - Derek Orr, Mar 12 2015
a(n*(n+3)/2) = a(A000096(n)) = 2^n. - Derek Orr, Mar 12 2015
Recurrence for fixed n: T(n, k) = -(k+2)*(k+1)/(2*(n-k)) * T(n, k+2), starting with T(n, n) = 2^n. - Ralf Stephan, Mar 26 2016
The m-th row consecutive nonzero entries in increasing order are (-1)^(c/2)*(c+b)!/(c/2)!b!*2^b with c = m, m-2, ..., 0 and b = m-c if m is even and with c = m-1, m-3, ..., 0 with b = m-c if m is odd. For the 10th row starting at a(55) the 6 consecutive nonzero entries in order are -30240,302400,-403200,161280,-23040,1024 given by c = 10,8,6,4,2,0 and b = 0,2,4,6,8,10. - Richard Turk, Aug 20 2017

A000321 H_n(-1/2), where H_n(x) is Hermite polynomial of degree n.

Original entry on oeis.org

1, -1, -1, 5, 1, -41, 31, 461, -895, -6481, 22591, 107029, -604031, -1964665, 17669471, 37341149, -567425279, -627491489, 19919950975, 2669742629, -759627879679, 652838174519, 31251532771999, -59976412450835, -1377594095061119, 4256461892701199, 64623242860354751
Offset: 0

Views

Author

Keywords

Comments

Binomial transform gives A067994. Inverse binomial transform gives A062267(n)*(-1)^n. - Vladimir Reshetnikov, Oct 11 2016
The congruence a(n+k) == (-1)^k*a(n) (mod k) holds for all n and k. It follows that for even k the sequence obtained by reducing a(n) modulo k is purely periodic with period a divisor of k, while for odd k the sequence obtained by reducing a(n) modulo k is purely periodic with period a divisor of 2*k. See A047974. - Peter Bala, Apr 10 2023

References

  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 209.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Programs

  • Magma
    m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Exp(-x-x^2))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Jun 09 2018
  • Mathematica
    Table[HermiteH[n, -1/2], {n, 0, 25}] (* Vladimir Joseph Stephan Orlovsky, Jun 15 2009 *)
    Table[(-2)^n HypergeometricU[-n/2, 1/2, 1/4], {n, 0, 25}] (* Benedict W. J. Irwin, Oct 17 2017 *)
  • PARI
    N=66;  x='x+O('x^N);
    egf=exp(-x-x^2);  Vec(serlaplace(egf))
    /* Joerg Arndt, Mar 07 2013 */
    
  • PARI
    vector(50, n, n--; sum(k=0, n/2, (-1)^(n-k)*k!*binomial(n, k)*binomial(n-k, k))) \\ Altug Alkan, Oct 22 2015
    
  • PARI
    a(n) = polhermite(n, -1/2); \\ Michel Marcus, Oct 12 2016
    
  • Python
    from sympy import hermite
    def a(n): return hermite(n, -1/2) # Indranil Ghosh, May 26 2017
    

Formula

E.g.f.: exp(-x-x^2).
a(n) = Sum_{k=0..floor(n/2)} (-1)^(n-k)*k!*C(n, k)*C(n-k, k).
a(n) = - a(n-1) - 2*(n-1)*a(n-2), a(0) = 1, a(1) = -1.
a(n) = Sum_{k=0..n} (-1)^(2*n-k)*C(k,n-k)*n!/k!. - Paul Barry, Oct 08 2007, corrected by Altug Alkan, Oct 22 2015
E.g.f.: 1 - x*(1 - E(0) )/(1+x) where E(k) = 1 - (1+x)/(k+1)/(1-x/(x+1/E(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Jan 18 2013
E.g.f.: -x/Q(0) where Q(k) = 1 - (1+x)/(1 - x/(x - (k+1)/Q(k+1) )); (continued fraction). - Sergei N. Gladkovskii, Mar 06 2013
G.f.: 1/(x*Q(0)), where Q(k) = 1 + 1/x + 2*(k+1)/Q(k+1) ; (continued fraction). - Sergei N. Gladkovskii, Dec 21 2013
a(n) = (-2)^n * U(-n/2, 1/2, 1/4), where U is the confluent hypergeometric function. - Benedict W. J. Irwin, Oct 17 2017
E.g.f.: Product_{k>=1} (1 + (-x)^k)^(mu(k)/k). - Ilya Gutkovskiy, May 26 2019

Extensions

Formulae and more terms from Vladeta Jovovic, Apr 30 2001

A122021 a(n) = a(n-2) - (n-1)*a(n-3), with a(0) = 0, a(1) = 1, a(2) = 2.

Original entry on oeis.org

0, 1, 2, 1, -1, -7, -6, -1, 43, 47, 52, -383, -465, -1007, 4514, 5503, 19619, -66721, -73932, -419863, 1193767, 1058777, 10010890, -25204097, -14340981, -265465457, 615761444, 107400049, 7783328783, -17133920383, 4668727362
Offset: 0

Views

Author

Roger L. Bagula, Sep 12 2006

Keywords

Crossrefs

Programs

  • GAP
    a:= function(n)
        if n<3 then return n;
        else return a(n-2) - (n-1)*a(n-3);
        fi;
      end;
    List([0..30], n-> a(n) ); # G. C. Greubel, Oct 06 2019
  • Magma
    I:=[0,1,2]; [n le 3 select I[n] else Self(n-2) - (n-2)*Self(n-3): n in [1..30]]; // G. C. Greubel, Oct 06 2019
    
  • Maple
    a:= proc(n) option remember;
    if n < 3 then n
    else a(n-2)-(n-1)*a(n-3)
    fi;
    end proc;
    seq(a(n), n = 0..30); # G. C. Greubel, Oct 06 2019
  • Mathematica
    a[0]=0; a[1]=1; a[2]=2; a[n_]:= a[n]= a[n-2] - (n-1)*a[n-3]; Table[a[n], {n, 0, 30}]
    RecurrenceTable[{a[0]==0,a[1]==1,a[2]==2,a[n]==a[n-2]-(n-1)a[n-3]},a,{n,30}] (* Harvey P. Dale, Apr 29 2022 *)
  • PARI
    my(m=30, v=concat([0,1,2], vector(m-3))); for(n=4, m, v[n] = v[n-2] - (n-2)*v[n-3]); v \\ G. C. Greubel, Oct 06 2019
    
  • Sage
    def a(n):
        if (n<3): return n
        else: return a(n-2) - (n-1)* a(n-3)
    [a(n) for n in (0..30)] # G. C. Greubel, Oct 06 2019
    

Extensions

Edited by N. J. A. Sloane, Sep 12 2006
Offset changed by G. C. Greubel, Oct 06 2019

A122022 a(n) = a(n-1) - (n-1)*a(n-4), with a(0) = 0, a(1) = 1, a(2) = 2, a(3) = 1.

Original entry on oeis.org

0, 1, 2, 1, 1, -3, -13, -19, -26, -2, 115, 305, 591, 615, -880, -5150, -14015, -23855, -8895, 83805, 350090, 827190, 1013985, -829725, -8881795, -28734355, -54083980, -32511130, 207297335, 1011859275, 2580294695, 3555628595, -2870588790, -35250085590
Offset: 0

Views

Author

Roger L. Bagula, Sep 12 2006

Keywords

Crossrefs

Programs

  • GAP
    a:= function(n)
        if n<3 then return n;
        elif n=3 then return 1;
        else return a(n-1) - (n-1)*a(n-4);
        fi;
      end;
    List([1..30], n-> a(n) ); # G. C. Greubel, Oct 06 2019
  • Magma
    I:=[0,1,2,1]; [n le 4 select I[n] else Self(n-1) - (n-2)*Self(n-4): n in [1..30]]; // G. C. Greubel, Oct 06 2019
    
  • Maple
    a:= proc(n) option remember;
          if n<3 then n
        elif n=3 then 1
        else a(n-1) - (n-1)*a(n-4)
          fi;
    end: seq(a(n), n=0..30); # G. C. Greubel, Oct 06 2019
  • Mathematica
    a[0]=0; a[1]=1; a[2]=2; a[3]=1; a[n_]:= a[n]= a[n-1] - (n-1)*a[n-4]; Table[a[n], {n, 0, 30}]
    RecurrenceTable[{a[0]==0,a[1]==1,a[2]==2,a[3]==1,a[n]==a[n-1]- (n-1) a[n-4]},a,{n,0,30}] (* Harvey P. Dale, Nov 28 2014 *)
  • PARI
    my(m=30, v=concat([0,1,2,1], vector(m-4))); for(n=5, m, v[n] = v[n-1] - (n-2)*v[n-4]); v \\ G. C. Greubel, Oct 06 2019
    
  • Sage
    @CachedFunction
    def a(n):
        if (n<3): return n
        elif (n==3): return 1
        else: return a(n-1) - (n-1)*a(n-4)
    [a(n) for n in (0..30)] # G. C. Greubel, Oct 06 2019
    

Extensions

Edited by N. J. A. Sloane, Sep 12 2006
Offset corrected by Georg Fischer, Jun 06 2021

A369738 Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of e.g.f. exp(1 - (1+x)^k).

Original entry on oeis.org

1, 1, 0, 1, -1, 0, 1, -2, 1, 0, 1, -3, 2, -1, 0, 1, -4, 3, 4, 1, 0, 1, -5, 4, 21, -20, -1, 0, 1, -6, 5, 56, -63, 8, 1, 0, 1, -7, 6, 115, -104, -423, 184, -1, 0, 1, -8, 7, 204, -95, -2464, 1899, -464, 1, 0, 1, -9, 8, 329, 36, -8245, 1696, 15201, -1648, -1, 0
Offset: 0

Views

Author

Seiichi Manyama, Jan 30 2024

Keywords

Examples

			Square array T(n,k) begins:
  1,  1,   1,    1,     1,      1,       1, ...
  0, -1,  -2,   -3,    -4,     -5,      -6, ...
  0,  1,   2,    3,     4,      5,       6, ...
  0, -1,   4,   21,    56,    115,     204, ...
  0,  1, -20,  -63,  -104,    -95,      36, ...
  0, -1,   8, -423, -2464,  -8245,  -21096, ...
  0,  1, 184, 1899,  1696, -21275, -124344, ...
		

Crossrefs

Columns k=0..5 give A000007, A033999, (-1)^n * A062267(n), A369751, A369752, A369753.
Main diagonal gives A369754.

Programs

  • PARI
    a000587(n) = sum(k=0, n, (-1)^k*stirling(n, k, 2));
    T(n, k) = sum(j=0, n, k^j*stirling(n, j, 1)*a000587(j));

Formula

T(0,k) = 1; T(n,k) = -k * (n-1)! * Sum_{j=1..min(k,n)} binomial(k-1,j-1) * T(n-j,k)/(n-j)!.
T(n,k) = Sum_{j=0..n} k^j * Stirling1(n,j) * A000587(j).

A144141 a(n) = Hermite(n,2).

Original entry on oeis.org

1, 4, 14, 40, 76, -16, -824, -3104, -880, 46144, 200416, -121216, -4894016, -16666880, 60576896, 708980224, 1018614016, -18612911104, -109084520960, 233726715904, 5080118660096, 10971406004224, -169479359707136, -1160659303014400, 3153413334470656
Offset: 0

Views

Author

Keywords

Crossrefs

Programs

  • Magma
    [(&+[(-1)^k*Factorial(n)*(4)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]]): n in [0..30]]; // G. C. Greubel, Jul 10 2018
  • Mathematica
    lst={};Do[AppendTo[lst,HermiteH[n,2]],{n,0,7^2}];lst
    HermiteH[Range[0,30],2]  (* Harvey P. Dale, May 20 2012 *)
  • PARI
    for(n=0, 50, print1(polhermite(n, 2), ", " )) \\ G. C. Greubel, Jul 10 2018
    

Formula

From G. C. Greubel, Jul 10 2018: (Start)
E.g.f.: exp(4*x - x^2).
a(n) = Sum_{k=0..floor(n/2)} (-1)^k*n!*4^(n-2*k)/(k!*(n-2*k)!). (End)

A122033 a(n) = 2*a(n-1) - 2*(n-2)*a(n-2), with a(0)=1, a(1)=2.

Original entry on oeis.org

1, 2, 4, 4, -8, -40, -16, 368, 928, -3296, -21440, 16448, 461696, 561536, -9957632, -34515200, 209783296, 1455022592, -3803020288, -57076808704, 22755112960, 2214428956672, 3518653394944, -85968709390336, -326758168158208, 3301044295639040, 22286480662872064
Offset: 0

Views

Author

Roger L. Bagula, Sep 13 2006

Keywords

Crossrefs

Programs

  • GAP
    a:=[1,2];; for n in [3..35] do a[n]:=2*(a[n-1]-(n-3)*a[n-2]); od; a; # G. C. Greubel, Oct 04 2019
  • Magma
    I:=[1,2]; [n le 2 select I[n] else 2*(Self(n-1)-(n-3)*Self(n-2)): n in [1..35]]; // G. C. Greubel, Oct 04 2019
    
  • Maple
    a:= proc(n) option remember;
          if n < 2 then n+1
        else 2*(a(n-1) - (n-2)*a(n-2))
          fi
        end proc:
    seq(a(n), n = 0..35); # G. C. Greubel, Oct 04 2019
  • Mathematica
    a[n_]:= a[n]= If[n<2, n+1, a[n-1]-(n-2)*a[n-2]]; Table[a[n], {n,0,30}] (* modified by G. C. Greubel, Oct 04 2019 *)
    nxt[{n_,a_,b_}]:={n+1,b,2b-2a(n-1)}; NestList[nxt,{1,1,2},30][[;;,2]] (* Harvey P. Dale, Jan 01 2024 *)
  • PARI
    my(m=35, v=concat([1,2], vector(m-2))); for(n=3, m, v[n] = 2*(v[n-1] - (n-3)*v[n-2] ) ); v \\ G. C. Greubel, Oct 04 2019
    
  • Sage
    def a(n):
        if n<2: return n+1
        else: return 2*(a(n-1) - (n-2)*a(n-2))
    [a(n) for n in (0..35)] # G. C. Greubel, Oct 04 2019
    

Formula

a(n) = 2*a(n-1) - 2*(n-2)*a(n-2), with a(0)=1, a(1)=2. - G. C. Greubel, Oct 04 2019
a(n) = 2*A062267(n-1) for n > 0. - Michel Marcus, Oct 05 2019
E.g.f.: 1 + exp(1)*sqrt(Pi)*( erf(1) - erf(1-x) ), where erf(x) is the error function. - G. C. Greubel, Oct 05 2019

Extensions

Edited by N. J. A. Sloane, Sep 17 2006
Corrected and offset changed by G. C. Greubel, Oct 04 2019

A181089 Triangle T(n, k) = A060821(n,k) + A060821(n,n-k), read by rows.

Original entry on oeis.org

2, 2, 2, 2, 0, 2, 8, -12, -12, 8, 28, 0, -96, 0, 28, 32, 120, -160, -160, 120, 32, -56, 0, 240, 0, 240, 0, -56, 128, -1680, -1344, 3360, 3360, -1344, -1680, 128, 1936, 0, -17024, 0, 26880, 0, -17024, 0, 1936, 512, 30240, -9216, -80640, 48384, 48384, -80640, -9216, 30240, 512
Offset: 0

Views

Author

Roger L. Bagula, Oct 02 2010

Keywords

Examples

			Triangle begins as:
     2;
     2,     2;
     2,     0,      2;
     8,   -12,    -12,      8;
    28,     0,    -96,      0,      28;
    32,   120,   -160,   -160,     120,    32;
   -56,     0,    240,      0,     240,     0,     -56;
   128, -1680,  -1344,   3360,    3360, -1344,   -1680,   128;
  1936,     0, -17024,      0,   26880,     0,  -17024,     0,   1936;
   512, 30240,  -9216, -80640,   48384, 48384,  -80640, -9216,  30240, 512;
		

Crossrefs

Programs

  • Mathematica
    (* First program *)
    p[x_, n_] = HermiteH[n, x] + ExpandAll[x^n*HermiteH[n, 1/x]];
    Flatten[Table[CoefficientList[p[x, n], x], {n, 0, 15}]] (* edited by G. C. Greubel, Apr 04 2021 *)
    (* Second program *)
    A060821[n_, k_]:= If[EvenQ[n-k], (-1)^(Floor[(n-k)/2])*2^k*n!/(k!*(Floor[(n - k)/2]!)), 0];
    T[n_, k_]:= A060821[n, k] +A060821[n, n-k];
    Table[T[n, k], {n,0,15}, {k,0,n}]//Flatten (* G. C. Greubel, Apr 04 2021 *)
  • Sage
    def A060821(n,k): return (-1)^((n-k)//2)*2^k*factorial(n)/(factorial(k)*factorial( (n-k)//2)) if (n-k)%2==0 else 0
    def T(n,k): return A060821(n, k) + A060821(n, n-k)
    flatten([[T(n,k) for k in (0..n)] for n in (0..15)]) # G. C. Greubel, Apr 04 2021

Formula

T(n, k) = coefficients [x^k] of the polynomial HermiteH(n,x) + x^n*HermiteH(n,1/x).
T(n, k) = A060821(n,k) + A060821(n,n-k).
Sum_{k=0..n} T(n, k) = 2*A062267(n).

A277378 Expansion of e.g.f. exp(2*x/(1-x))/sqrt(1-x^2).

Original entry on oeis.org

1, 2, 9, 50, 361, 3042, 29929, 331298, 4100625, 55777922, 828691369, 13316140818, 230256982201, 4257449540450, 83834039024649, 1750225301567618, 38614608429012001, 897325298084953602, 21904718673762721225, 560258287738117292018, 14981472258320814527241
Offset: 0

Views

Author

Vladimir Reshetnikov, Oct 11 2016

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Abs[HermiteH[n, I]]^2/2^n, {n, 0, 20}]
    With[{nn=20},CoefficientList[Series[Exp[2x/(1-x)]/Sqrt[1-x^2],{x,0,nn}],x] Range[ 0,nn]!] (* Harvey P. Dale, Jan 27 2023 *)

Formula

E.g.f.: exp(2*x/(1-x))/sqrt(1-x^2).
a(n) = |H_n(i)|^2 / 2^n = H_n(i) * H_n(-i) / 2^n, where H_n(x) is n-th Hermite polynomial, i = sqrt(-1).
D-finite with recurrence: (n+2)*(a(n) + n*a(n-1)) = a(n+1) + n*(n-1)^2*a(n-2).
a(n) ~ n^n / (2 * exp(1 - 2*sqrt(2*n) + n)) * (1 + 2*sqrt(2)/(3*sqrt(n))). - Vaclav Kotesovec, Oct 27 2021

A025165 a(n) = H_n(1) / 2^floor(n/2) where H_n is the n-th Hermite polynomial.

Original entry on oeis.org

1, 2, 1, -2, -5, -2, 23, 58, -103, -670, 257, 7214, 4387, -77794, -134825, 819466, 2841841, -7427774, -55739071, 22221790, 1081264139, 1718092478, -20988454441, -79774943398, 402959508745
Offset: 0

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Programs

  • Magma
    [((&+[(-1)^k*Factorial(n)*(2)^(n-2*k)/( Factorial(k) *Factorial(n-2*k)): k in [0..Floor(n/2)]]))/2^(Floor(n/2)): n in [0..30]]; // G. C. Greubel, Jul 10 2018
  • Maple
    A025165 := proc(n)
        HermiteH(n,1)/2^(floor(n/2)) ;
        simplify(%) ;
    end proc: # R. J. Mathar, Feb 05 2013
  • Mathematica
    Table[ HermiteH[ n, 1 ]/2^Floor[ n/2 ], {n, 0, 24} ]
  • PARI
    for(n=0,30, print1(polhermite(n,1)/2^(floor(n/2)), ", ")) \\ G. C. Greubel, Jul 10 2018
    

Formula

a(n) = A062267(n)/A016116(n). - R. J. Mathar, Feb 05 2013
Conjecture: a(n) +a(n-1) +(2*n-5)*a(n-2) +(2*n-7)*a(n-3) +(n-2)*(n-3)*a(n-4) +(n-3)*(n-4)*a(n-5)=0. - R. J. Mathar, Feb 25 2015
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