Original entry on oeis.org
42, -3171, 515242, -88552695, 16361485098, -3146078130083, 622295456184618, -125653124401054383, 25774485201611434666, -5353054527354475135971, 1122995842490069166600618, -237552033781060445940477047, 50601782105864798623718932266
Offset: 1
-
terms = 13;
E2[x_] = 1 - 24*Sum[k*x^k/(1 - x^k), {k, 1, terms}];
E4[x_] = 1 + 240*Sum[k^3*x^k/(1 - x^k), {k, 1, terms}];
E6[x_] = 1 - 504*Sum[k^5*x^k/(1 - x^k), {k, 1, terms}];
a[n_] := (1/(24 n))*Sum[MoebiusMu[n/d]*SeriesCoefficient[E4[x]/E2[x] - E6[x]/E4[x], {x, 0, d}], {d, Divisors[n]}];
Array[a, terms] (* Jean-François Alcover, Feb 26 2018 *)
Original entry on oeis.org
0, 654403831, -428244362959801779753, 280244748103684391377173184156636, -183393234406846382045882997606216500971256873, 120013233624492418923583549710011469008178874255627685075, -78537118839697516276808630128261511971322824900859081926520601647268
Offset: 0
A110163
Exponents a(1), a(2), ... such that theta series of E_8 lattice, 1 + 240 q + 2160 q^2 + ... (A004009) is equal to (1-q)^a(1) (1-q^2)^a(2) (1-q^3)^a(3) ...
Original entry on oeis.org
-240, 26760, -4096240, 708938760, -130880766192, 25168873498760, -4978357936128240, 1005225129317834760, -206195878414962688240, 42824436296045618358408, -8983966738037593190400240, 1900416270294787067711818760, -404814256845771786255876096240, 86744167089111545378556727322760
Offset: 1
From _Seiichi Manyama_, Jun 17 2017: (Start)
a(1) = 8 + 1/3 * A008683(1/1) * A288261(1) = 8 + 1/3 * (-744) = -240,
a(2) = 8 + 1/6 * (A008683(2/1) * A288261(1) + A008683(2/2) * A288261(2)) = 8 + 1/6 * (744 + 159768) = 26760. (End)
-
terms = 14; Clear[a, sol];
a4009[n_] := If[n == 0, 1, 240 DivisorSigma[3, n]];
sol[0] = {}; sol[kmax_] := sol[kmax] = Join[sol[kmax-1], SolveAlways[ Sum[ a4009[k] q^k, {k, 0, kmax}] == Normal[Product[(1-q^k)^a[k], {k, 1, kmax}] + O[q]^(kmax+1)] /. sol[kmax-1], q][[1]] ];
A110163 = Array[a, terms] /. sol[terms] (* Jean-François Alcover, Jul 03 2017 *)
A289209
Coefficients in expansion of E_4^3/E_6^2.
Original entry on oeis.org
1, 1728, 1700352, 1332930816, 939690602496, 624182333927040, 399031077924476928, 248370528839869094400, 151578005556161702559744, 91116938989182168182098368, 54119528875319902426524072960, 31833210323194251819350736777984
Offset: 0
(E_4^3/E_6^2)^(k/288):
A289365 (k=1),
A299694 (k=2),
A299696 (k=3),
A299697 (k=4),
A299698 (k=6),
A299943 (k=8),
A299949 (k=9),
A289369 (k=12),
A299950 (k=16),
A299951 (k=18),
A299953 (k=24),
A299993 (k=32),
A299994 (k=36),
A300052 (k=48),
A300053 (k=72),
A300054 (k=96),
A300055 (k=144), this sequence (k=288).
-
nmax = 20; CoefficientList[Series[(1 + 240*Sum[DivisorSigma[3,k]*x^k, {k, 1, nmax}])^3 / (1 - 504*Sum[DivisorSigma[5,k]*x^k, {k, 1, nmax}])^2, {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 08 2017 *)
A289210
Coefficients in expansion of E_6^2/E_4^3.
Original entry on oeis.org
1, -1728, 1285632, -616294656, 242544070656, -85253786824320, 27846073156184064, -8638345400999827968, 2579332695698905989120, -747814048389765750131136, 211795259563761765262894080, -58852853362216364363212075776
Offset: 0
(E_6^2/E_4^3)^(k/288):
A289366 (k=1),
A296609 (k=2),
A296614 (k=3),
A296652 (k=4),
A297021 (k=6),
A299422 (k=8),
A299862 (k=9),
A289368 (k=12),
A299856 (k=16),
A299857 (k=18),
A299858 (k=24),
A299863 (k=32),
A299859 (k=36),
A299860 (k=48),
A299861 (k=72),
A299414 (k=96),
A299413 (k=144), this sequence (k=288).
-
nmax = 20; CoefficientList[Series[(1 - 504*Sum[DivisorSigma[5,k]*x^k, {k, 1, nmax}])^2 / (1 + 240*Sum[DivisorSigma[3,k]*x^k, {k, 1, nmax}])^3, {x, 0, nmax}], x] (* Vaclav Kotesovec, Jul 08 2017 *)
A192731
Euler transform is 1 / (q j(q)) where j is j-function (A000521).
Original entry on oeis.org
-744, 80256, -12288744, 2126816256, -392642298600, 75506620496256, -14935073808384744, 3015675387953504256, -618587635244888064744, 128473308888136855075200, -26951900214112779571200744
Offset: 1
From _Seiichi Manyama_, Jun 18 2017: (Start)
a(1) = (1/1) * A008683(1/1) * A288261(1) = (1/1) * (-744) = -744,
a(2) = (1/2) * (A008683(2/1) * A288261(1) + A008683(2/2) * A288261(2)) = (1/2) * (744 + 159768) = 80256. (End)
-
{a(n) = local(A, S); if( n<1, 0, A = 1 + x * O(x^n); S = x * ellj( x * A ); for( k = 1, n-1, S *= (A - x^k) ^ polcoeff( S, k)); - polcoeff( S, n))}
A288840
Coefficients in expansion of E_8/E_6.
Original entry on oeis.org
1, 984, 574488, 307081056, 164453203992, 88062998451984, 47157008244215904, 25252184242734325440, 13522333949728177520664, 7241096993206804017918456, 3877547016709833498690361488, 2076394071353012138642420600352
Offset: 0
G.f.: 1 + 984*q + 574488*q^2 + 307081056*q^3 + 164453203992*q^4 + 88062998451984*q^5 + 47157008244215904*q^6 + ...
From _Seiichi Manyama_, Jun 27 2017: (Start)
a(0) = j_0(i) = 1,_
a(1) = j_1(i) = -744 + 1728^1 = 984,
a(2) = j_2(i) = 159768 - 1488*1728^1 + 1728^2 = 574488. (End)
- Ken Ono, The Web of Modularity: Arithmetic of the Coefficients of Modular Forms and q-series, CBMS Regional Conference Series in Mathematics, vol. 102, American Mathematical Society, Providence, RI, 2004.
-
nmax = 20; CoefficientList[Series[(1 + 480*Sum[DivisorSigma[7, k]*x^k, {k, 1, nmax}])/(1 - 504*Sum[DivisorSigma[5, k]*x^k, {k, 1, nmax}]), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 28 2017 *)
terms = 12; Ei[n_] = 1-(2n/BernoulliB[n]) Sum[k^(n-1) x^k/(1-x^k), {k, terms}]; CoefficientList[Ei[8]/Ei[6] + O[x]^terms, x] (* Jean-François Alcover, Mar 01 2018 *)
A288877
Coefficients in expansion of E_4/E_2.
Original entry on oeis.org
1, 264, 8568, 231456, 6214872, 166719024, 4472485344, 119980322880, 3218631807384, 86344077536616, 2316294684846288, 62137684699355232, 1666926011246777184, 44717506621139113584, 1199606572169515887552, 32181041313068138778816
Offset: 0
-
nmax = 20; CoefficientList[Series[(1 + 240*Sum[DivisorSigma[3, k]*x^k, {k, 1, nmax}])/(1 - 24*Sum[DivisorSigma[1, k]*x^k, {k, 1, nmax}]), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 28 2017 *)
terms = 16; Ei[n_] = 1-(2n/BernoulliB[n]) Sum[k^(n-1) x^k/(1-x^k), {k, terms}]; CoefficientList[Ei[4]/Ei[2] + O[x]^terms, x] (* Jean-François Alcover, Mar 01 2018 *)
A289029
Exponents a(1), a(2), ... such that E_14, 1 - 24*q - 196632*q^2 + ... (A058550) is equal to (1-q)^a(1) (1-q^2)^a(2) (1-q^3)^a(3) ... .
Original entry on oeis.org
24, 196908, 42987544, 21974456220, 8544538312728, 3980088408377644, 1793770730037338136, 847156322106368439324, 401870774532436947447832, 193962999708079363021283628, 94363580764388112933729226776, 46332621615483591171320408201116
Offset: 1
A289024
Exponents a(1), a(2), ... such that E_10, 1 - 264*q - 135432*q^2 + ... (A013974) is equal to (1-q)^a(1) (1-q^2)^a(2) (1-q^3)^a(3) ... .
Original entry on oeis.org
264, 170148, 47083784, 21265517460, 8675419078920, 3954919534878884, 1798749087973466376, 846151096977050604564, 402076970410851910136072, 193920175271783317402925220, 94372564731126150526919627016, 46330721199213296384252696382356
Offset: 1
Showing 1-10 of 18 results.
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