A051619
a(n) = (4*n+7)(!^4)/7(!^4), related to A034176(n+1) ((4*n+3)(!^4) quartic, or 4-factorials).
Original entry on oeis.org
1, 11, 165, 3135, 72105, 1946835, 60351885, 2112315975, 82380323025, 3542353890075, 166490632833525, 8491022274509775, 467006225098037625, 27553367280784219875, 1735862138689405852125, 116302763292190192092375
Offset: 0
-
m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1/(1-4*x)^(11/4))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Aug 15 2018
-
s=1;lst={s};Do[s+=n*s;AppendTo[lst, s], {n, 10, 5!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 08 2008 *)
With[{nn = 30}, CoefficientList[Series[1/(1 - 4*x)^(11/4), {x, 0, nn}], x]*Range[0, nn]!] (* G. C. Greubel, Aug 15 2018 *)
-
x='x+O('x^30); Vec(serlaplace(1/(1-4*x)^(11/4))) \\ G. C. Greubel, Aug 15 2018
A051621
a(n) = (4*n+9)(!^4)/9(!^4), related to A007696(n+1) ((4*n+1)(!^4) quartic, or 4-factorials).
Original entry on oeis.org
1, 13, 221, 4641, 116025, 3364725, 111035925, 4108329225, 168441498225, 7579867420125, 371413503586125, 19684915690064625, 1122040194333683625, 68444451854354701125, 4448889370533055573125, 306973366566780834545625
Offset: 0
-
m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1/(1-4*x)^(13/4))); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, Aug 15 2018
-
s=1;lst={s};Do[s+=n*s;AppendTo[lst, s], {n, 12, 5!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 08 2008 *)
With[{nn = 30}, CoefficientList[Series[1/(1 - 4*x)^(13/4), {x, 0, nn}], x]*Range[0, nn]!] (* G. C. Greubel, Aug 15 2018 *)
-
x='x+O('x^30); Vec(serlaplace(1/(1-4*x)^(13/4))) \\ G. C. Greubel, Aug 15 2018
A370915
A(n, k) = 4^n*Pochhammer(k/4, n). Square array read by ascending antidiagonals.
Original entry on oeis.org
1, 0, 1, 0, 1, 1, 0, 5, 2, 1, 0, 45, 12, 3, 1, 0, 585, 120, 21, 4, 1, 0, 9945, 1680, 231, 32, 5, 1, 0, 208845, 30240, 3465, 384, 45, 6, 1, 0, 5221125, 665280, 65835, 6144, 585, 60, 7, 1, 0, 151412625, 17297280, 1514205, 122880, 9945, 840, 77, 8, 1
Offset: 0
The array starts:
[0] 1, 1, 1, 1, 1, 1, 1, 1, 1, ...
[1] 0, 1, 2, 3, 4, 5, 6, 7, 8, ...
[2] 0, 5, 12, 21, 32, 45, 60, 77, 96, ...
[3] 0, 45, 120, 231, 384, 585, 840, 1155, 1536, ...
[4] 0, 585, 1680, 3465, 6144, 9945, 15120, 21945, 30720, ...
[5] 0, 9945, 30240, 65835, 122880, 208845, 332640, 504735, 737280, ...
.
Seen as the triangle T(n, k) = A(n - k, k):
[0] 1;
[1] 0, 1;
[2] 0, 1, 1;
[3] 0, 5, 2, 1;
[4] 0, 45, 12, 3, 1;
[5] 0, 585, 120, 21, 4, 1;
[6] 0, 9945, 1680, 231, 32, 5, 1;
[7] 0, 208845, 30240, 3465, 384, 45, 6, 1;
Columns:
A000007,
A007696,
A001813,
A008545,
A047053,
A007696,
A000407,
A034176,
A052570 and
A034177,
A051617,
A051618,
A051619,
A051620.
-
A := (n, k) -> 4^n*pochhammer(k/4, n):
for n from 0 to 5 do seq(A(n, k), k = 0..9) od;
T := (n, k) -> A(n - k, k): seq(seq(T(n, k), k = 0..n), n = 0..9);
# Using the exponential generating functions of the columns:
EGFcol := proc(k, len) local egf, ser, n; egf := (1 - 4*x)^(-k/4);
ser := series(egf, x, len+2): seq(n!*coeff(ser, x, n), n = 0..len) end:
seq(lprint(EGFcol(n, 9)), n = 0..5);
# Using the generating polynomials for the rows:
P := (n, x) -> local k; add(Stirling1(n, k)*(-4)^(n - k)*x^k, k=0..n):
seq(lprint([n], seq(P(n, k), k = 0..8)), n = 0..5);
# Implementing the LU decomposition of A:
with(LinearAlgebra):
L := Matrix(7, 7, (n, k) -> A371026(n-1, k-1)):
U := Matrix(7, 7, (n, k) -> binomial(n-1, k-1)):
MatrixMatrixMultiply(L, Transpose(U));
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A[n_, k_] := 4^n * Pochhammer[k/4, n]; Table[A[n - k, k], {n, 0, 9}, {k, 0, n}] // Flatten (* Amiram Eldar, Mar 06 2024 *)
-
def A(n, k): return 4**n * rising_factorial(k/4, n)
for n in range(6): print([A(n, k) for k in range(9)])
A052570
E.g.f.: x/(1-4*x).
Original entry on oeis.org
0, 1, 8, 96, 1536, 30720, 737280, 20643840, 660602880, 23781703680, 951268147200, 41855798476800, 2009078326886400, 104472072998092800, 5850436087893196800, 351026165273591808000, 22465674577509875712000
Offset: 0
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
-
spec := [S,{S=Prod(Z,Sequence(Union(Z,Z,Z,Z)))},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
-
With[{nn=20},CoefficientList[Series[x/(1-4x),{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Jan 15 2017 *)
A081407
4th-order non-linear ("factorial") recursion: a(0)=a(1)=a(2)=a(3)=1, a(n) = (n+1)*a(n-4).
Original entry on oeis.org
1, 1, 1, 1, 5, 6, 7, 8, 45, 60, 77, 96, 585, 840, 1155, 1536, 9945, 15120, 21945, 30720, 208845, 332640, 504735, 737280, 5221125, 8648640, 13627845, 20643840, 151412625, 259459200, 422463195, 660602880, 4996616625, 8821612800
Offset: 0
Following sequences are interleaved: A007696: {5,45,585,..}; A000404: {6,60,840,..} A034176: {7,77,1155,..}; A034177: {8,96,1536,..}
-
a:= function(k)
if k<4 then return 1;
elif k<7 then return k+1;
else return (k+1)*a(k-4);
fi;
end;
List([0..35], n-> a(n) ); # G. C. Greubel, Aug 24 2019
-
a081407 n = a081408_list !! n
a081407_list = 1 : 1 : 1 : 1 : zipWith (*) [5..] a081407_list
-- Reinhard Zumkeller, Jan 05 2012
-
a:= func< n | n le 3 select 1 else n in [4..6] select n+1 else (n+1)*Self(n-3) >;
[a(n): n in [0..35]]; // G. C. Greubel, Aug 24 2019
-
f[n_]:= (n+1)*f[n-4]; f[0]=1; f[1]=1; f[2]=1; f[3]=1; Table[f[n], {n, 0, 40}]
nxt[{n_,a_,b_,c_,d_}]:={n+1,b,c,d,a(n+2)}; NestList[nxt,{3,1,1,1,1},40][[;;,2]] (* Harvey P. Dale, Jan 13 2025 *)
-
a(n) = if(n<4, 1, (n+1)*a(n-4) );
vector(35, n, a(n-1)) \\ G. C. Greubel, Aug 24 2019
-
def a(n):
if n<4: return 1
elif 4<= n <= 6: return n+1
else: return (n+1)*a(n-4)
[a(n) for n in (0..35)] # G. C. Greubel, Aug 24 2019
A098560
Expansion of e.g.f. (1+4*x)/(1-4*x).
Original entry on oeis.org
1, 8, 64, 768, 12288, 245760, 5898240, 165150720, 5284823040, 190253629440, 7610145177600, 334846387814400, 16072626615091200, 835776583984742400, 46803488703145574400, 2808209322188734464000, 179725396620079005696000
Offset: 0
-
[1] cat [2^(2*n+1)*Factorial(n): n in [2..30]]; // G. C. Greubel, Jan 17 2018
-
s=2;lst={1};Do[s+=n*s+s;AppendTo[lst, s], {n, 2, 5!, 4}];lst (* Vladimir Joseph Stephan Orlovsky, Nov 08 2008 *)
With[{nn=20},CoefficientList[Series[(1+4x)/(1-4x),{x,0,nn}],x] Range[0,nn]!] (* or *) Join[{1},Table[2*4^n n!,{n,20}]] (* Harvey P. Dale, Jan 16 2012 *)
-
for(n=0, 30, print1(if(n==0,1, 2^(2*n+1)*n!), ", ")) \\ G. C. Greubel, Jan 17 2018
A081408
a(n) = (n+1)*a(n-5), with a(0)=a(1)=a(2)=a(3)=a(4)=1.
Original entry on oeis.org
1, 1, 1, 1, 1, 6, 7, 8, 9, 10, 66, 84, 104, 126, 150, 1056, 1428, 1872, 2394, 3000, 22176, 31416, 43056, 57456, 75000, 576576, 848232, 1205568, 1666224, 2250000, 17873856, 27143424, 39783744, 56651616, 78750000, 643458816, 1004306688, 1511782272
Offset: 0
A008548, A034323, A034300, A034301, A034325 sequences are combed together as A081408(5n+r) with r=0,1,2,3,4.
Cf.
A001147,
A002866,
A034001,
A007599,
A034000,
A007696,
A000407,
A034176,
A034177,
A008548,
A034323,
A034300,
A034301,
A034325 [double, triple, quartic, quintic, factorial subsequences], generated together in
A081405-
A081408.
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a:=[1,1,1,1,1];; for n in [6..40] do a[n]:=n*a[n-5]; od; a; # G. C. Greubel, Aug 15 2019
-
a081407 n = a081408_list !! n
a081407_list = 1 : 1 : 1 : 1 : zipWith (*) [5..] a081407_list
-- Reinhard Zumkeller, Jan 05 2012
-
[n le 5 select 1 else n*Self(n-5): n in [1..40]]; // G. C. Greubel, Aug 15 2019
-
a[0]=a[1]=a[2]=a[3]=a[4]=1; a[x_]:= (x+1)*a[x-5]; Table[a[n], {n, 40}]
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m=30; v=concat([1,1,1,1,1], vector(m-5)); for(n=6, m, v[n]=n*v[n-5] ); v \\ G. C. Greubel, Aug 15 2019
-
def a(n):
if (n<5): return 1
else: return (n+1)*a(n-5)
[a(n) for n in (0..40)] # G. C. Greubel, Aug 15 2019
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