A101612
n! * Sum[k=floor(n/2)..n, 1/k].
Original entry on oeis.org
3, 11, 26, 154, 684, 5508, 35664, 361296, 3068640, 37383840, 392722560, 5584394880, 69878833920, 1135360800000, 16484477184000, 301158902016000, 4976250951168000, 100951141777920000, 1870345490614272000
Offset: 2
A052767
Expansion of e.g.f.: -(log(1-x))^5.
Original entry on oeis.org
0, 0, 0, 0, 0, 120, 1800, 21000, 235200, 2693880, 32319000, 410031600, 5519487600, 78864820320, 1194924450720, 19166592681600, 324817601472000, 5803921108010880, 109115988701293440, 2154085473710580480, 44566174481427360000, 964537418717406213120, 21799797542483649131520
Offset: 0
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
-
spec := [S,{B=Cycle(Z),S=Prod(B,B,B,B,B)},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
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With[{nn=20},CoefficientList[Series[-(Log[1-x])^5,{x,0,nn}],x] Range[0,nn]!] (* Harvey P. Dale, Oct 14 2019 *)
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a(n) = {5!*stirling(n,5,1)*(-1)^(n+1)} \\ Andrew Howroyd, Jul 27 2020
A052779
Expansion of e.g.f.: (log(1-x))^6.
Original entry on oeis.org
0, 0, 0, 0, 0, 0, 720, 15120, 231840, 3265920, 45556560, 649479600, 9604465200, 148370508000, 2402005525920, 40797624067200, 726963917097600, 13580328282393600, 265689107448756480, 5437099866285377280, 116229410301685651200, 2591985252922277184000, 60218914823672258142720
Offset: 0
encyclopedia(AT)pommard.inria.fr, Jan 25 2000
-
spec := [S,{B=Cycle(Z),S=Prod(B,B,B,B,B,B)},labeled]: seq(combstruct[count](spec,size=n), n=0..20);
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a(n) = {6!*stirling(n,6,1)*(-1)^n} \\ Andrew Howroyd, Jul 27 2020
Name changed and terms a(20) and beyond from
Andrew Howroyd, Jul 27 2020
A129841
Antidiagonal sums of triangle T defined in A048594: T(j,k) = k! * Stirling1(j,k), 1<= k <= j.
Original entry on oeis.org
1, -1, 4, -12, 52, -256, 1502, -10158, 78360, -680280, 6574872, -70075416, 816909816, -10342968456, 141357740736, -2074340369088, 32530886655168, -542971977209760, 9610316495698416, -179788450082431536, 3544714566466060032
Offset: 1
First seven rows of T are
[ 1 ]
[ -1, 2 ]
[ 2, -6, 6 ]
[ -6, 22, -36, 24 ]
[ 24, -100, 210, -240, 120 ]
[ -120, 548, -1350, 2040, -1800, 720 ]
[ 720, -3528, 9744, -17640, 21000, -15120, 5040 ]
- P. Curtz, Integration numerique des systemes differentiels a conditions initiales. Note no. 12 du Centre de Calcul Scientifique de l'Armement, 1969, 135 pages, p. 61. Available from Centre d'Electronique de L'Armement, 35170 Bruz, France, or INRIA, Projets Algorithmes, 78150 Rocquencourt.
- P. Curtz, Gazette des Mathematiciens, 1992, no. 52, p. 44.
- P. Flajolet, X. Gourdon and B. Salvy, Gazette des Mathematiciens, 1993, no. 55, pp. 67-78.
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m:=21; T:=[ [ Factorial(k)*StirlingFirst(j, k): k in [1..j] ]: j in [1..m] ]; [ &+[ T[j-k+1][k]: k in [1..(j+1) div 2] ]: j in [1..m] ]; // Klaus Brockhaus, Jun 03 2007
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m = 21; t[j_, k_] := k!*StirlingS1[j, k]; Total /@ Table[ t[j-k+1, k], {j, 1, m}, {k, 1, Quotient[j+1, 2]}] (* Jean-François Alcover, Aug 13 2012, translated from Klaus Brockhaus's Magma program *)
A304654
a(n) = (n!)^2 * Sum_{k=1..n-1} 1/(k^2*(n-k)).
Original entry on oeis.org
0, 0, 4, 27, 328, 6500, 192216, 7952112, 438941952, 31185057024, 2772643115520, 301622403456000, 39413353102848000, 6091955683706880000, 1099401414283210752000, 229088914497045356544000, 54589580461769879715840000, 14750581694440372638842880000
Offset: 0
-
Table[(n!)^2 * Sum[1/(k^2*(n-k)), {k, 1, n-1}], {n, 0, 20}]
A304655
a(n) = (n!)^3 * Sum_{k=1..n-1} 1/(k^3*(n-k)^2).
Original entry on oeis.org
0, 0, 8, 81, 2480, 175000, 23825904, 5563712448, 2051674085376, 1124193889529856, 873600549068759040, 927968580453961728000, 1307864687259363065856000, 2386263863328126193631232000, 5521179117888960788194394112000, 15917227342113559040727019683840000
Offset: 0
-
Table[(n!)^3 * Sum[1/(k^3*(n-k)^2), {k, 1, n-1}], {n, 0, 20}]
A308346
Expansion of e.g.f. 1/(1 - x)^log(1 - x).
Original entry on oeis.org
1, 0, -2, -6, -10, 20, 352, 2772, 18132, 104400, 469608, 238920, -35811048, -730972944, -11436661728, -164609993520, -2294024595312, -31488879303552, -426338226719904, -5626751283423072, -70000948158061728, -745703905072996800, -4142683990211677440, 110386551348875714880
Offset: 0
-
m:=30; R:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!( (1-x)^Log(1/(1-x)) )); [Factorial(n-1)*b[n]: n in [1..m]]; // G. C. Greubel, May 21 2019
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E:= 1/(1-x)^log(1-x):
S:= series(E,x,31):
seq(coeff(S,x,j)*j!,j=0..30); # Robert Israel, May 22 2019
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nmax = 23; CoefficientList[Series[1/(1 - x)^Log[1 - x], {x, 0, nmax}], x] Range[0, nmax]!
Table[Sum[Abs[StirlingS1[n, k]] HermiteH[k, 0], {k, 0, n}], {n, 0, 23}]
a[n_] := a[n] = -2 Sum[(k - 1)! HarmonicNumber[k - 1] Binomial[n - 1, k - 1] a[n - k], {k, 2, n}]; a[0] = 1; Table[a[n], {n, 0, 23}]
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a(n) = sum(k=0, n, abs(stirling(n, k, 1))*polhermite(k, 0)); \\ Michel Marcus, May 21 2019
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m = 30; T = taylor((1-x)^log(1/(1-x)), x, 0, m); [factorial(n)*T.coefficient(x, n) for n in (0..m)] # G. C. Greubel, May 21 2019
A333371
Exponential convolution of primorial numbers (A002110) with themselves.
Original entry on oeis.org
1, 4, 20, 132, 1116, 12420, 171300, 2884980, 56674380, 1289511300, 34769949060, 1063909626780, 37255008811020, 1470406699982220, 63114539746598340, 2936218980067393020, 150241360192861037100, 8497891914008911514100, 514514062115556069627060
Offset: 0
-
p:= proc(n) option remember; `if`(n<1, 1, ithprime(n)*p(n-1)) end:
a:= n-> add(p(i)*p(n-i)*binomial(n, i), i=0..n):
seq(a(n), n=0..20); # Alois P. Heinz, Mar 17 2020
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primorial[n_] := Product[Prime[k], {k, 1, n}]; a[n_] := Sum[Binomial[n, k] primorial[k] primorial[n - k], {k, 0, n}]; Table[a[n], {n, 0, 18}]
A156047
Triangle read by rows: T(n, k) = (n+1)!*(1/k + 1/(n-k+1)).
Original entry on oeis.org
4, 9, 9, 32, 24, 32, 150, 100, 100, 150, 864, 540, 480, 540, 864, 5880, 3528, 2940, 2940, 3528, 5880, 46080, 26880, 21504, 20160, 21504, 26880, 46080, 408240, 233280, 181440, 163296, 163296, 181440, 233280, 408240, 4032000, 2268000, 1728000, 1512000, 1451520, 1512000, 1728000, 2268000, 4032000
Offset: 1
Triangle begins as:
4;
9, 9;
32, 24, 32;
150, 100, 100, 150;
864, 540, 480, 540, 864;
5880, 3528, 2940, 2940, 3528, 5880;
46080, 26880, 21504, 20160, 21504, 26880, 46080;
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Flat(List([1..10], n-> List([1..n], k-> (n+1)*Factorial(n+1)/(k*(n-k+1)) ))); # G. C. Greubel, Dec 02 2019
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[(n+1)*Factorial(n+1)/(k*(n-k+1)): k in [1..n], n in [1..10]]; // G. C. Greubel, Dec 02 2019
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seq(seq( (n+1)*(n+1)!/(k*(n-k+1)), k=1..n), n=1..10); # G. C. Greubel, Dec 02 2019
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Table[(n+1)*(n+1)!/(k*(n-k+1)), {n,10}, {k,n}]//Flatten (* modified by G. C. Greubel, Dec 02 2019 *)
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T(n,k) = (n+1)*(n+1)!/(k*(n-k+1)); \\ G. C. Greubel, Dec 02 2019
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[[(n+1)*factorial(n+1)/(k*(n-k+1)) for k in (1..n)] for n in (1..10)] # G. C. Greubel, Dec 02 2019
A377394
Expansion of e.g.f. (1 - log(1-x))^3.
Original entry on oeis.org
1, 3, 9, 30, 120, 582, 3354, 22488, 172320, 1487208, 14284296, 151179696, 1748521296, 21945019392, 297077918976, 4315269544704, 66952906801920, 1105127533048320, 19337110495511040, 357542547031249920, 6965984564179246080, 142638952766943744000, 3062533108375448064000
Offset: 0
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a(n) = sum(k=0, 3, k!*binomial(3, k)*abs(stirling(n, k, 1)));
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