A089506
Denominators used in A089505 to compute column sequences of triangle A089504.
Original entry on oeis.org
1, 3, 27, 513, 540702, 8891844390, 27306854121690, 94235953573952190, 1684561906087969348440, 1106757172299795861925080, 8644064410182787098480243878401800, 289900692457541891469406183557646377576408600, 1206267931807293851480420134690207296382114287151076400
Offset: 1
-
a[n_, m_] := (-1)^(n-m)*FactorialPower[m+2, 3]^(n-1)/(Product[ FactorialPower[m+2, 3] - FactorialPower[r+2, 3], {r, 1, m-1}]*Product[ FactorialPower[r+2, 3] - FactorialPower[m+2, 3], {r, m+1, n}]); a[n_] := LCM @@ Table[Denominator[a[n, m]], {m, 1, n}]; Array[a, 11] (* Jean-François Alcover, Sep 02 2016 *)
A089504
A generalization of triangle A071951 (Legendre-Stirling).
Original entry on oeis.org
1, 6, 1, 36, 30, 1, 216, 756, 90, 1, 1296, 18360, 6156, 210, 1, 7776, 441936, 387720, 31356, 420, 1, 46656, 10614240, 23705136, 4150440, 119556, 756, 1, 279936, 254788416, 1432922400, 521757936, 29257200, 373572, 1260, 1, 1679616
Offset: 1
[1]; [6,1]; [36,30,1]; [216,756,90,1]; ...
a(3,2) = 30 = ((-1)*(3*2*1)^1 + 4*(4*3*2)^1)/3.
- R. B. Corcino, K. J. M. Gonzales, M. J. C. Loquias and E. L. Tan, Dually weighted Stirling-type sequences, arXiv preprint arXiv:1302.4694 [math.CO], 2013.
- R. B. Corcino, K. J. M. Gonzales, M. J. C. Loquias and E. L. Tan, Dually weighted Stirling-type sequences, Europ. J. Combin., 43, 2015, 55-67.
- W. Lang, First 8 rows.
Cf.
A071951 (Legendre-Stirling, (2, 2) case).
-
max = 10; f[m_] := 1/Product[1 - FactorialPower[r + 2, 3]*x, {r, 1, m}]; col[m_] := CoefficientList[f[m] + O[x]^(max - m + 1), x]; a[n_, m_] := col[m][[n - m + 1]]; Table[a[n, m], {n, 1, max}, {m, 1, n}] // Flatten (* Jean-François Alcover, Sep 01 2016 *)
Original entry on oeis.org
1, 90, 6156, 387720, 23705136, 1432922400, 86230132416, 5179923146880, 310942155338496, 18660051727004160, 1119687641441381376, 67183287394552842240, 4031045937469026349056, 241863924899255181189120
Offset: 0
-
CoefficientList[Series[1/(1-90 x+1944 x^2-8640 x^3),{x,0,20}],x] (* or *) LinearRecurrence[{90,-1944,8640},{1,90,6156},20] (* Harvey P. Dale, Jul 07 2021 *)
A090219
Signed triangle used to compute column sequences of array A078741 ((3,3)-Stirling2).
Original entry on oeis.org
1, -1, 4, 1, -8, 10, -1, 12, -30, 20, 1, -64, 600, -1600, 1225, -1, 80, -1000, 4000, -6125, 3136, 1, -96, 1500, -8000, 18375, -18816, 7056, -1, 448, -21000, 280000, -1500625, 3687936, -4148928, 1728000, 1, -512, 28000, -448000, 3001250, -9834496, 16595712, -13824000, 4492125, -1
Offset: 3
The third (k=5) column sequence of array A078741 is A078741(n+3,5)=c(5; n)= b(3)*(1*(3*2*1)^n -8*(4*3*2)^n +10*(5*4*3)^n), with b(3)= N(3)/A090220(3)=3/1=3, n>=0. This is 9*A089518.
The fifth (k=7) column sequence of array A078741 is A078741(n+3,7)=c(7; n)= b(5)*(1*(3*2*1)^n -64*(4*3*2)^n +600*(5*4*3)^n -1600*(6*5*4)^n +1225*(7*6*5)^n), with b(5)= N(5)/A090220(5)=3/2, n>=0. This is the sequence [243, 149580, 49658508, 13062960720,... ] which has a factor of 27.
Triangle begins:
[1];
[-1,4];
[1,-8,10];
[-1,12,-30,20];
[1,-64,600,-1600,1225];
...
Companion sequence
A090220 for denominators D(m).
A089507
Second column of triangle A089504 and second column of array A078741 divided by 18.
Original entry on oeis.org
1, 30, 756, 18360, 441936, 10614240, 254788416, 6115201920, 146766525696, 3522406694400, 84537821131776, 2028908069959680, 48693795855814656, 1168651113600245760, 28047626804770062336, 673143043784666480640
Offset: 0
-
[6^n*(4^(n+1)-1)/3: n in [0..15]]; // Vincenzo Librandi, Oct 18 2017
-
CoefficientList[Series[1/((1-6x)(1-24x)),{x,0,20}],x] (* or *) LinearRecurrence[{30,-144},{1,30},20] (* Harvey P. Dale, Sep 25 2017 *)
Original entry on oeis.org
1, 210, 31356, 4150440, 521757936, 64043874720, 7771495098816, 937759335004800, 112842062355914496, 13559707534436743680, 1628284591773850622976, 195461334300256627599360
Offset: 0
-
CoefficientList[Series[1/((1-6x)(1-24x)(1-60x)(1-120x)),{x,0,20}],x] (* or *) LinearRecurrence[ {210,-12744,241920,-1036800},{1,210,31356,4150440},20] (* Harvey P. Dale, Mar 17 2023 *)
Showing 1-6 of 6 results.
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