Original entry on oeis.org
1, -1, -4, -19, -55, 5179, 408149, 23366098, -2659962750, -2946880278857, -1715161696081878, 603927037021100215, 9904716216487281046207, 52286804207990141325901614, -71925062774291844591785748425, -17522340813140430159774329947096591
Offset: 0
-
require 'prime'
def power(a, n)
return 1 if n == 0
k = power(a, n >> 1)
k *= k
return k if n & 1 == 0
return k * a
end
def sigma(x, i)
sum = 1
pq = i.prime_division
if x == 0
pq.each{|a, n| sum *= n + 1}
else
pq.each{|a, n| sum *= (power(a, (n + 1) * x) - 1) / (power(a, x) - 1)}
end
sum
end
def A(k, m, n)
ary = [1]
s_ary = [0] + (1..n).map{|i| sigma(k, i * m)}
(1..n).each{|i| ary << (1..i).inject(0){|s, j| s - ary[-j] * s_ary[j]} / i}
ary
end
def A283333(n)
(0..n).map{|i| A(i + 1, 1, i)[-1]}
end
A073592
Euler transform of negative integers.
Original entry on oeis.org
1, -1, -2, -1, 0, 4, 4, 7, 3, -2, -9, -17, -25, -24, -13, -1, 32, 61, 97, 111, 112, 74, 8, -108, -243, -392, -512, -569, -542, -358, -33, 473, 1078, 1788, 2395, 2865, 2955, 2569, 1496, -245, -2751, -5783, -9121, -12299, -14739, -15806, -14719, -10930, -3813, 6593, 20284, 36139, 53081, 68620, 80539
Offset: 0
-
a:= proc(n) option remember; `if`(n=0, 1, -add(
numtheory[sigma][2](j)*a(n-j), j=1..n)/n)
end:
seq(a(n), n=0..60); # Alois P. Heinz, Mar 12 2015
-
nmax=50; CoefficientList[Series[Exp[Sum[-x^k/(k*(1-x^k)^2),{k,1,nmax}]],{x,0,nmax}],x] (* Vaclav Kotesovec, Mar 02 2015 *)
a[n_]:= a[n] = -1/n*Sum[DivisorSigma[2,k]*a[n-k],{k,1,n}]; a[0]=1; Table[a[n],{n,0,100}] (* Vaclav Kotesovec, Mar 02 2015 *)
-
# uses[EulerTransform from A166861]
b = EulerTransform(lambda n: -n)
print([b(n) for n in range(55)]) # Peter Luschny, Nov 11 2020
A144048
Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is Euler transform of (j->j^k).
Original entry on oeis.org
1, 1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 5, 6, 5, 1, 1, 9, 14, 13, 7, 1, 1, 17, 36, 40, 24, 11, 1, 1, 33, 98, 136, 101, 48, 15, 1, 1, 65, 276, 490, 477, 266, 86, 22, 1, 1, 129, 794, 1828, 2411, 1703, 649, 160, 30, 1, 1, 257, 2316, 6970, 12729, 11940, 5746, 1593, 282, 42, 1, 1, 513
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, ...
2, 3, 5, 9, 17, 33, ...
3, 6, 14, 36, 98, 276, ...
5, 13, 40, 136, 490, 1828, ...
7, 24, 101, 477, 2411, 12729, ...
-
with(numtheory): etr:= proc(p) local b; b:= proc(n) option remember; `if`(n=0,1, add(add(d*p(d), d=divisors(j)) *b(n-j), j=1..n)/n) end end: A:= (n,k)-> etr(j->j^k)(n); seq(seq(A(n,d-n), n=0..d), d=0..13);
-
etr[p_] := Module[{ b}, b[n_] := b[n] = If[n == 0, 1, Sum[Sum[d*p[d], {d, Divisors[j]}]*b[n - j], {j, 1, n}]/n]; b]; A[n_, k_] := etr[Function[j, j^k]][n]; Table[Table[A[n, d - n], {n, 0, d}], {d, 0, 13}] // Flatten (* Jean-François Alcover, Dec 27 2013, translated from Maple *)
A283263
Expansion of exp( Sum_{n>=1} -sigma_3(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -4, -5, -1, 21, 49, 81, 45, -121, -484, -997, -1344, -840, 1624, 6931, 15149, 23155, 23469, 2240, -57596, -168929, -322587, -461165, -450668, -64135, 985621, 2935044, 5718865, 8597971, 9683008, 5596899, -8414092, -37295629, -83336988, -141108721
Offset: 0
Cf.
A023871 (exp( Sum_{n>=1} sigma_3(n)*x^n/n )).
-
a[n_] := If[n<1, 1,-(1/n) * Sum[DivisorSigma[3, k] a[n - k], {k, n}]]; Table[a[n], {n, 0, 35}] (* Indranil Ghosh, Mar 16 2017 *)
-
a(n) = if(n<1, 1, -(1/n) * sum(k=1, n, sigma(k, 3) * a(n - k)));
for(n=0, 35, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 16 2017
-
# uses[EulerTransform from A166861]
b = EulerTransform(lambda n: -n^2)
print([b(n) for n in range(36)]) # Peter Luschny, Nov 11 2020
A283271
Expansion of exp( Sum_{n>=1} -sigma_5(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -16, -65, -55, 807, 4809, 13135, 550, -169070, -862710, -2281174, -1221309, 20194565, 114391575, 346400092, 486546751, -1239516671, -11089537215, -41702958960, -93143227027, -45337210750, 674845109986, 3682196642725, 11405949184465, 20796945542222
Offset: 0
Cf.
A023873 (exp( Sum_{n>=1} sigma_5(n)*x^n/n )).
A283264
Expansion of exp( Sum_{n>=1} -sigma_4(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -8, -19, -9, 127, 500, 1038, 448, -4967, -21463, -50043, -59084, 70418, 600080, 1837349, 3532062, 3179251, -6965009, -42260393, -119597290, -224546234, -223670132, 292245783, 2156083245, 6428174973, 13030612271, 16820582355, -133402359, -78307103593
Offset: 0
Cf.
A023872 (exp( Sum_{n>=1} sigma_4(n)*x^n/n )).
A284992
Square array A(n,k), n>=0, k>=0, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1+x^j)^(j^k) in powers of x.
Original entry on oeis.org
1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 4, 5, 2, 1, 1, 8, 13, 8, 3, 1, 1, 16, 35, 31, 16, 4, 1, 1, 32, 97, 119, 83, 28, 5, 1, 1, 64, 275, 457, 433, 201, 49, 6, 1, 1, 128, 793, 1763, 2297, 1476, 487, 83, 8, 1, 1, 256, 2315, 6841, 12421, 11113, 4962, 1141, 142, 10, 1, 1
Offset: 0
Square array begins:
1, 1, 1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, 1, 1, ...
1, 2, 4, 8, 16, 32, 64, 128, ...
2, 5, 13, 35, 97, 275, 793, 2315, ...
2, 8, 31, 119, 457, 1763, 6841, 26699, ...
3, 16, 83, 433, 2297, 12421, 68393, 382573, ...
4, 28, 201, 1476, 11113, 85808, 678101, 5466916, ...
5, 49, 487, 4962, 52049, 561074, 6189117, 69540142, ...
-
b:= proc(n, i, k) option remember; `if`(n=0, 1, `if`(i<1, 0,
add(b(n-i*j, i-1, k)*binomial(i^k, j), j=0..n/i)))
end:
A:= (n, k)-> b(n$2, k):
seq(seq(A(n, d-n), n=0..d), d=0..14); # Alois P. Heinz, Oct 16 2017
-
b[n_, i_, k_] := b[n, i, k] = If[n == 0, 1, If[i < 1, 0,
Sum[b[n - i*j, i - 1, k]*Binomial[i^k, j], {j, 0, n/i}]]];
A[n_, k_] := b[n, n, k];
Table[Table[A[n, d - n], {n, 0, d}], {d, 0, 14}] // Flatten (* Jean-François Alcover, Feb 10 2021, after Alois P. Heinz *)
A283336
Expansion of exp( Sum_{n>=1} -sigma_6(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -32, -211, -285, 5179, 44784, 162062, -125122, -5187417, -32587255, -95706881, 122837972, 3039216222, 17745876032, 52825817007, -24340390929, -1256623249600, -7805634068163, -26364952524572, -20649978457115, 368666542515083, 2777231006764690
Offset: 0
Cf.
A023874 (exp( Sum_{n>=1} sigma_6(n)*x^n/n )).
-
a[n_] := If[n<1, 1,-(1/n) * Sum[DivisorSigma[6, k] a[n - k], {k, n}]]; Table[a[n], {n, 0, 22}] (* Indranil Ghosh, Mar 16 2017 *)
-
a(n) = if(n<1, 1, -(1/n) * sum(k=1, n, sigma(k, 6) * a(n - k)));
for(n=0, 22, print1(a(n), ", ")) \\ Indranil Ghosh, Mar 16 2017
A283337
Expansion of exp( Sum_{n>=1} -sigma_7(n)*x^n/n ) in powers of x.
Original entry on oeis.org
1, -1, -64, -665, -1351, 33111, 408149, 1959491, -4502590, -149420286, -1182474566, -3678670450, 22384197409, 377982157035, 2474860645111, 6161653683590, -48899064011245, -695916857379611, -4275491639488601, -10750056317745704, 69316545348329853
Offset: 0
Cf.
A023875 (exp( Sum_{n>=1} sigma_7(n)*x^n/n )).
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 )).
Showing 1-10 of 14 results.
Comments