A283338
Expansion of exp( Sum_{n>=1} -sigma_8(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -128, -2059, -6069, 210067, 3664420, 23366098, -116899962, -4133365357, -41809923367, -125160180169, 2447495850838, 42931762306584, 321967686614676, 281683012498569, -23874414003295851, -318729240693402530, -1992572289343189863
Offset: 0
Cf.
A023876 (exp( Sum_{n>=1} sigma_8(n)*x^n/n )).
A283339
Expansion of exp( Sum_{n>=1} -sigma_9(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -256, -6305, -26335, 1321887, 32565169, 276211695, -2659962750, -111341327890, -1454216029918, -3323783801026, 227018039015019, 4636828146319845, 39615489757794355, -132865771935151820, -9075288352543844755, -132703303201618610765
Offset: 0
Cf.
A023877 (exp( Sum_{n>=1} sigma_9(n)*x^n/n )).
A283340
Expansion of exp( Sum_{n>=1} -sigma_10(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -512, -19171, -111645, 8255899, 287477144, 3248973702, -56353404842, -2946880278857, -50078654012311, -24091665240825, 19437354184565824, 486126425619195338, 4607922953609319032, -63107867988829247005, -3101395214088243725145
Offset: 0
Cf.
A023878 (exp( Sum_{n>=1} sigma_10(n)*x^n/n )).
A299211
Expansion of 1/(1 - x*Product_{k>=1} (1 - x^k)^k).
Original entry on oeis.org
1, 1, 0, -3, -6, -4, 12, 39, 52, -9, -186, -392, -285, 610, 2291, 3200, -150, -10626, -23487, -18841, 32957, 134848, 198246, 13961, -605248, -1409604, -1234474, 1744213, 7898753, 12209679, 2161666, -34344627, -84393284, -79993042, 90692470, 461463974, 749309529, 207447895, -1939084232
Offset: 0
Cf.
A067687,
A073592,
A299105,
A299106,
A299108,
A299162,
A299164,
A299166,
A299167,
A299208,
A299209,
A299210,
A299212.
-
N:= 100: # for a(0)..a(N)
S:= series(1/(1-x*mul((1-x^k)^k,k=1..N)),x,N+1):
seq(coeff(S,x,i),i=0..N); # Robert Israel, Feb 05 2023
-
nmax = 38; CoefficientList[Series[1/(1 - x Product[(1 - x^k)^k, {k, 1, nmax}]), {x, 0, nmax}], x]
A318784
Expansion of Product_{k>=1} 1/(1 - x^k)^(sigma_1(k)-k), where sigma_1(k) = sum of divisors of k (A000203).
Original entry on oeis.org
1, 0, 1, 1, 4, 2, 11, 6, 25, 20, 56, 44, 139, 107, 283, 266, 619, 567, 1317, 1242, 2680, 2705, 5403, 5539, 10947, 11339, 21291, 23013, 41494, 45213, 79991, 88312, 151546, 170908, 284901, 324421, 532505, 611227, 981002, 1142000, 1797451, 2105773, 3268765, 3855050, 5889704, 7004451
Offset: 0
-
with(numtheory):
a:= proc(n) option remember; `if`(n=0, 1, add(add(d*
(sigma(d)-d), d=divisors(j))*a(n-j), j=1..n)/n)
end:
seq(a(n), n=0..50); # Alois P. Heinz, Sep 03 2018
-
nmax = 45; CoefficientList[Series[Product[1/(1 - x^k)^(DivisorSigma[1, k] - k), {k, 1, nmax}], {x, 0, nmax}], x]
nmax = 45; CoefficientList[Series[Exp[Sum[DivisorSigma[2, k] x^(2 k)/(k (1 - x^k)), {k, 1, nmax}]], {x, 0, nmax}], x]
a[n_] := a[n] = If[n == 0, 1, Sum[Sum[d (DivisorSigma[1, d] - d), {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 45}]
A294404
E.g.f.: exp(-Sum_{n>=1} sigma_2(n) * x^n).
Original entry on oeis.org
1, -1, -9, -31, -23, 3399, 41311, 473129, 1284081, -79051537, -2447228249, -52444297071, -712806368999, -2221410364681, 331443685309647, 15068893004257049, 460836352976093281, 10298306504802529119, 122928784866003823831, -3359583359629857247807
Offset: 0
E.g.f.: exp(-Sum_{n>=1} sigma_k(n) * x^n):
A294402 (k=0),
A294403 (k=1), this sequence (k=2).
A294808
Square array A(n,k), n >= 0, k >= 0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1-j^(k*j)*x^j)^j in powers of x.
Original entry on oeis.org
1, 1, -1, 1, -1, -2, 1, -1, -8, -1, 1, -1, -32, -73, 0, 1, -1, -128, -2155, -927, 4, 1, -1, -512, -58921, -259701, -13969, 4, 1, -1, -2048, -1593811, -67045719, -48496253, -254580, 7, 1, -1, -8192, -43044673, -17178209325, -152513227585, -13001952944, -5288596, 3
Offset: 0
Square array begins:
1, 1, 1, 1, 1, ...
-1, -1, -1, -1, -1, ...
-2, -8, -32, -128, -512, ...
-1, -73, -2155, -58921, -1593811, ...
0, -927, -259701, -67045719, -17178209325, ...
4, -13969, -48496253, -152513227585, -476819162106101, ...
A301624
G.f. A(x) satisfies: A(x) = Product_{k>=1} (1 - x^k*A(x)^k)^k.
Original entry on oeis.org
1, -1, -1, 4, 1, -17, -6, 118, -8, -876, 625, 5966, -7486, -41937, 75969, 306312, -768637, -2164992, 7487063, 14461466, -70259884, -89410774, 646971980, 459817892, -5861484630, -1128608133, 52082250637, -15894742662, -453574650852, 366848121166, 3866670213663, -5215687717614
Offset: 0
G.f. A(x) = 1 - x - x^2 + 4*x^3 + x^4 - 17*x^5 - 6*x^6 + 118*x^7 - 8*x^8 - 876*x^9 + 625*x^10 + ...
G.f. A(x) satisfies: A(x) = (1 - x*A(x)) * (1 - x^2*A(x)^2)^2 * (1 - x^3*A(x)^3)^3 * (1 - x^4*A(x)^4)^4 * ...
log(A(x)) = -x - 3*x^2/2 + 8*x^3/3 + 13*x^4/4 - 51*x^5/5 - 120*x^6/6 + 538*x^7/7 + 781*x^8/8 - 5419*x^9/9 - 3053*x^10/10 + ... + A281267(n)*x^n/n + ...
Cf.
A000219,
A006195,
A066398,
A073592,
A109085,
A181315,
A278428,
A281267,
A301455,
A301456,
A301625.
-
with(numtheory):
Order := 33:
Gser := solve(series(x*exp(add(sigma[2](n)*x^n/n, n = 1..32)), x) = y, x):
seq(coeff(Gser, y^k), k = 1..32); # Peter Bala, Feb 09 2020
A303173
a(n) = [x^n] Product_{k=1..n} (1 - x^k)^(n-k+1).
Original entry on oeis.org
1, -1, 0, 4, -7, 0, 13, 10, -92, 21, 720, -2019, 1193, 6281, -18054, 16111, 11059, -14653, -57685, -86620, 1281406, -3454742, 2383734, 9409968, -30397071, 43327680, -56130326, 128981571, -73487834, -1219918457, 5059678044, -7826243881, -4131571113, 38850603452
Offset: 0
a(0) = 1;
a(1) = [x^1] (1 - x) = -1;
a(2) = [x^2] (1 - x)^2*(1 - x^2) = 0;
a(3) = [x^3] (1 - x)^3*(1 - x^2)^2*(1 - x^3) = 4;
a(4) = [x^4] (1 - x)^4*(1 - x^2)^3*(1 - x^3)^2*(1 - x^4) = -7;
a(5) = [x^5] (1 - x)^5*(1 - x^2)^4*(1 - x^3)^3*(1 - x^4)^2*(1 - x^5) = 0, etc.
...
The table of coefficients of x^k in expansion of Product_{k=1..n} (1 - x^k)^(n-k+1) begins:
n = 0: (1), 0, 0, 0, 0, 0, ...
n = 1: 1, (-1), 0, 0, 0, 0, ...
n = 2: 1, -2, (0), 2, -1, 0, ...
n = 3: 1, -3, 1, (4), -2, -2, ...
n = 4: 1, -4, 3, 6, (-7), -2, ...
n = 5: 1, -5, 6, 7, -16, (0), ...
-
Table[SeriesCoefficient[Product[(1 - x^k)^(n - k + 1), {k, 1, n}], {x, 0, n}], {n, 0, 33}]
A276552
Expansion of Product_{k>0} (1 - x^k)^(k*3).
Original entry on oeis.org
1, -3, -3, 8, 12, 9, -29, -54, -51, 8, 168, 273, 270, -18, -546, -1220, -1539, -969, 796, 3693, 6591, 8098, 5412, -2568, -16053, -31524, -42195, -38684, -11868, 41994, 117630, 193365, 235497, 197758, 42852, -247224, -639547, -1041432, -1291425, -1184100, -520650
Offset: 0
Comments