A091401
Numbers n such that genus of group Gamma_0(n) is zero.
Original entry on oeis.org
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 16, 18, 25
Offset: 1
- G. Shimura, Introduction to the Arithmetic Theory of Automorphic Functions, Princeton, 1971, see Prop. 1.40 and 1.43.
- Miranda C. N. Cheng, John F. R. Duncan and Jeffrey A Harvey, Umbral moonshine and the Niemeier lattices, Research in the Mathematical Sciences, 2014, 1:3; See Eq. (22). - _N. J. A. Sloane_, Jun 19 2014
- K. Harada, "Moonshine" of Finite Groups, European Math. Soc., 2010, p. 15.
- Yang-Hui He, John McKay, Sporadic and Exceptional, arXiv:1505.06742 [math.AG], 2015.
- Robert S. Maier, On Rationally Parametrized Modular Equations, arXiv:math/0611041 [math.NT], 2006.
- K. 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. See p. 110.
- B. Schoeneberg, Elliptic Modular Functions, Springer-Verlag, NY, 1974, p. 103.
The table below is a consequence of Theorem 7.3 in Maier's paper.
N EntryID K alpha
1
-
Flatten@ Position[#, 0] &@ Table[If[n < 1, 0, 1 + Sum[MoebiusMu[d]^2 n/d/12 - EulerPhi[GCD[d, n/d]]/2, {d, Divisors@ n}] - Count[(#^2 - # + 1)/n & /@ Range@ n, ?IntegerQ]/3 - Count[(#^2 + 1)/n & /@ Range@ n, ?IntegerQ]/4], {n, 120}] (* Michael De Vlieger, Dec 05 2016, after Michael Somos at A001617 *)
A276019
n^2 * a(n) = (88*n^2 - 132*n + 54) * a(n-1) - 500*(2*n-3)^2 * a(n-2), with a(0)=1, a(1)=10.
Original entry on oeis.org
1, 10, 230, 6500, 199750, 6366060, 204990300, 6539387400, 202432551750, 5897526329500, 151804596385780, 2807347223915000, -15232296765302500, -5584390420089725000, -416025902106681525000, -24002385182809425846000, -1235898175219724085176250, -59486502796252242452122500, -2731496764897242177292037500, -120874274801920384164027025000, -5181210157044172846922944311500
Offset: 0
A(x) = 1 + 10*x + 230*x^2 + 6500*x^3 + ... is the g.f.
-
seq(N) = {
a = vector(N); a[1] = 10; a[2] = 230;
for (n = 3, N, a[n] = ((88*n^2 - 132*n + 54)*a[n-1] - 500*(2*n-3)^2 * a[n-2])/n^2);
concat(1, a);
};
seq(20)
A276020
n^2 * a(n) = 2*(17*n^2-21*n+9) * a(n-1) - 4*(112*n^2-280*n+197) * a(n-2) + 40*(68*n^2-256*n+251) * a(n-3) - 1600*(2*n-5)^2 * a(n-4), with a(0)=1, a(1)=10, a(2)=90, a(3)=780.
Original entry on oeis.org
1, 10, 90, 780, 6630, 55820, 469220, 3967000, 33951750, 295553500, 2622492940, 23701797800, 217528135900, 2018704327800, 18862262001800, 176834576018480, 1659586559786950, 15575074941839100, 146164364053448700, 1372547571923176200, 12910383388613518580, 121770360957324308200, 1152648798132152849400
Offset: 0
-
a[0] = 1; a[1] = 10; a[2] = 90; a[3] = 780; a[n_] := a[n] = (40(68n^2 - 256n + 251)a[n-3] - 4(112n^2 - 280n + 197)a[n-2] + 2(17n^2 - 21n + 9)a[n-1] - 1600(2n - 5)^2 a[n-4])/n^2;
Table[a[n], {n, 0, 22}] (* Jean-François Alcover, Oct 19 2018 *)
-
seq(N) = {
my(a = vector(N));
a[1] = 10; a[2] = 90; a[3] = 780; a[4] = 6630;
for (n = 5, N,
my(t1 = 2*(17*n^2 - 21*n + 9)*a[n-1] - 4*(112*n^2 - 280*n + 197)*a[n-2],
t2 = 40*(68*n^2 - 256*n + 251) * a[n-3] - 1600*(2*n-5)^2 *a[n-4]);
a[n] = (t1 + t2)/n^2);
concat(1,a);
};
seq(22)
A276021
n^2 * a(n) = 3*(39*n^2 - 52*n + 20) * a(n-1) - 441*(3*n-4)^2 * a(n-2), with a(0)=1, a(1)=21.
Original entry on oeis.org
1, 21, 693, 23940, 734643, 13697019, -494620749, -83079255420, -6814815765975, -444980496382695, -25071954462140859, -1226361084729855984, -49426887403935395172, -1287188243957889124740, 23935850133162849385308, 6798920856226697943604944, 650950202721260061404073891
Offset: 0
A(x) = 1 + 21*x + 693*x^2 + 23940*x^3 + ... is the g.f.
-
I:=[21,693]; [1] cat [n le 2 select I[n] else (3*(39*n^2-52*n+20)*Self(n-1)-441*(3*n-4)^2*Self(n-2)) div n^2: n in [1..30]]; // Vincenzo Librandi, Aug 25 2016
-
a[0] = 1; a[1] = 21; a[n_] := a[n] = (3(39n^2 - 52n + 20) a[n-1] - 441(3n - 4)^2 a[n-2])/n^2;
Table[a[n], {n, 0, 16}] (* Jean-François Alcover, Oct 19 2018 *)
-
seq(N) = {
my(a = vector(N)); a[1] = 21; a[2] = 693;
for (n=3, N,
a[n] = (3*(39*n^2 - 52*n + 20) * a[n-1] - 441*(3*n-4)^2 * a[n-2])/n^2);
concat(1,a);
};
seq(17)
A276022
n^2 * a(n) = 3*(5*n^2 - 5*n + 2) * a(n-1) - 16*(5*n^2 - 10*n + 6) * a(n-2) + 36*(5*n^2 - 15*n + 12) * a(n-3) - 144*(n-2)^2 * a(n-4), with a(0)=1, a(1)=6, a(2)=30, a(3)=144.
Original entry on oeis.org
1, 6, 30, 144, 690, 3348, 16536, 83232, 426618, 2223180, 11756052, 62959680, 340881792, 1862954784, 10262937600, 56926831104, 317632207194, 1781352834300, 10034760283356, 56748881420640, 322033934657628, 1833043230774360, 10462349697348528, 59861990921495616
Offset: 0
A(x) = 1 + 6*x + 30*x^2 + 144*x^3 + ... is the g.f.
-
I:=[6,30,144,690]; [1] cat [n le 4 select I[n] else (3*(5*n^2-5*n+2)*Self(n-1)-16*(5*n^2-10*n+6)*Self(n-2)+36*(5*n^2-15*n+12)*Self(n-3)-144*(n-2)^2*Self(n-4)) div n^2: n in [1..30]]; // Vincenzo Librandi, Aug 25 2016
-
a[0] = 1; a[1] = 6; a[2] = 30; a[3] = 144; a[n_] := a[n] = (3(5n^2 - 5n + 2) a[n-1] - 16(5n^2 - 10n + 6)a[n-2] + 36(5n^2 - 15n + 12) a[n-3] - 144(n-2)^2 a[n-4])/n^2;
Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Oct 19 2018 *)
-
seq(N) = {
my(a = vector(N)); a[1] = 6; a[2] = 30; a[3] = 144; a[4] = 690;
for (n=5, N,
my(t1 = 3*(5*n^2 - 5*n + 2)*a[n-1] - 16*(5*n^2 - 10*n + 6)*a[n-2],
t2 = 36*(5*n^2 - 15*n + 12)*a[n-3] - 144*(n-2)^2 * a[n-4]);
a[n] = (t1+t2)/n^2);
concat(1,a);
};
seq(25)
A276177
n^2 * a(n) = 6*(66*n^2 - 94*n + 41) * a(n-1) - 36*(2016*n^2 - 5712*n + 4387) * a(n-2) + 50544*(132*n^2 - 560*n + 609) * a(n-3) - 7884864*(6*n-17)^2*a(n-4), with a(0)=1, a(1)=78, a(2)=4446, a(3)=20124.
Original entry on oeis.org
1, 78, 4446, 20124, -38185290, -6138851004, -560711991060, -21068540562888, 3057536757534246, 744702083933794740, 85203074089262120004, 5052846560269468159368, -180318018879496001303748, -86176724948835065345458008, -11276003918572185562671306600, -751248675388448553292016521104
Offset: 0
A(x) = 1 + 78*x + 4446*x^2 + 20124*x^3 + ... is the g.f.
-
I:=[78,4446,20124,-38185290]; [1] cat [n le 4 select I[n] else (6*(66*n^2-94*n+41)*Self(n-1)-36*(2016*n^2-5712*n+4387)*Self(n-2)+50544*(132*n^2-560*n+ 609)*Self(n-3)-7884864*(6*n-17)^2*Self(n-4)) div n^2: n in [1..30]]; // Vincenzo Librandi, Aug 25 2016
-
a[0] = 1; a[1] = 78; a[2] = 4446; a[3] = 20124; a[n_] := a[n] = (6(66n^2 - 94n + 41) a[n-1] - 36(2016n^2 - 5712n + 4387)a[n-2] + 50544(132n^2 - 560n + 609)a[n-3] - 7884864(6n - 17)^2 a[n-4])/n^2;
Table[a[n], {n, 0, 15}] (* Jean-François Alcover, Oct 19 2018 *)
-
seq(N) = {
my(a = vector(N));
a[1] = 78; a[2] = 4446; a[3] = 20124; a[4] = -38185290;
for (n = 5, N,
my(t1 = 6*(66*n^2 - 94*n + 41) * a[n-1],
t2 = -36*(2016*n^2 - 5712*n + 4387) * a[n-2],
t3 = 50544*(132*n^2 - 560*n + 609) * a[n-3],
t4 = -7884864*(6*n-17)^2 * a[n-4]);
a[n] = (t1 + t2 + t3 + t4)/n^2);
concat(1,a);
};
seq(17)
A276178
G.f.: 1/AGM(1, (1-4*x)^2).
Original entry on oeis.org
1, 4, 12, 32, 84, 240, 784, 2816, 10404, 38096, 137456, 493440, 1783376, 6532288, 24245568, 90814464, 341776164, 1289126160, 4870386736, 18439692928, 70004793936, 266551445952, 1017708956224, 3894679004160, 14932998810896, 57349426579264, 220574904103872, 849571289810432
Offset: 0
A(x) = 1 + 4*x + 12*x^2 + 32*x^3 + ... is the g.f.
-
a[n_] = DifferenceRoot[Function[{a, n}, {(-80 n^2 - 400n - 512) a[n+1] + (40n^2 + 240n + 368) a[n+2] + (-10n^2 - 70n - 124) a[n+3] + 64(n+2)^2 a[n] + (n+4)^2 a[n+4] == 0, a[0] == 1, a[1] == 4, a[2] == 12, a[3] == 32}]][n];
Table[a[n], {n, 0, 27}]
(* or: *)
Series[1/FunctionExpand[ArithmeticGeometricMean[1, (1-4x)^2], 1-4x > 0], {x, 0, 28}] // CoefficientList[#, x]& (* Jean-François Alcover, Dec 18 2018 *)
-
N=34; x='x + O('x^N); Vec(1/agm(1, (1-4*x)^2))
A276179
n^2 * a(n) = 2*(7*n^2 - 7*n + 3)*a(n-1) - 12*(7*n^2 - 14*n + 9)*a(n-2) + 39*(7*n^2 - 21*n + 18) * a(n-3) - 72*(7*n^2 - 28*n + 30)*a(n-4) + 72*(7*n^2 - 35*n + 45) * a(n-5) - 216*(n-3)^2 * a(n-6), with a(0)=1, a(1)=6, a(2)=24, a(3)=78, a(4)=216, a(5)=504.
Original entry on oeis.org
1, 6, 24, 78, 216, 504, 906, 756, -2808, -17832, -57312, -104832, 81882, 1734156, 9360576, 35755956, 106475472, 232967664, 215497680, -1178534304, -8734303296, -36146763648, -108833048064, -220247838720, -46688571558, 2220777704700, 13473296923536, 53523581091900
Offset: 0
A(x) = 1 + 6*x + 24*x^2 + 78*x^3 + 216*x^4 + 504*x^5 + 906*x^6 + ... is the g.f.
-
I:=[6,24,78,216,504,906]; [1] cat [n le 6 select I[n] else (2*(7*n^2-7*n+3)*Self(n-1)-12*(7*n^2-14*n+9)*Self(n-2)+39*(7*n^2-21*n+18)*Self(n-3)-72*(7*n^2-28*n+30)*Self(n-4)+72*(7*n^2-35*n+45)*Self(n-5)-216*(n-3)^2*Self(n-6)) div n^2: n in [1..30]]; // Vincenzo Librandi, Aug 25 2016
-
seq(N) = {
my(a = vector(N));
a[1] = 6; a[2] = 24; a[3] = 78; a[4] = 216; a[5] = 504; a[6] = 906;
for (n = 7, N,
my(t1 = 2*(7*n^2 - 7*n + 3)*a[n-1] - 12*(7*n^2 - 14*n + 9)*a[n-2],
t2 = 39*(7*n^2 - 21*n + 18) * a[n-3] - 72*(7*n^2 - 28*n + 30)*a[n-4],
t3 = 72*(7*n^2 - 35*n + 45) * a[n-5] - 216*(n-3)^2 * a[n-6]);
a[n] = (t1+t2+t3)/n^2);
concat(1,a);
};
seq(33)
A276180
n^2*a(n) = 2*(14*n^2 - 16*n + 7)*a(n-1) - 20*(24*n^2 - 56*n + 41)*a(n-2) + 80*(64*n^2 - 224*n + 221)*a(n-3) - 1600*(24*n^2 - 112*n + 139)*a(n-4) + 6400*(28*n^2 - 164*n + 245)*a(n-5) - 128000*(2*n-7)^2*a(n-6) for n>6, a(0)=1, a(1)=10, a(2)=30, a(3)=-300, a(4)=-3850, a(5)=-13940, a(6) = 56300.
Original entry on oeis.org
1, 10, 30, -300, -3850, -13940, 56300, 543400, -2332250, -29758500, 340835780, 7316239000, 40381709500, -199606565000, -4494519345000, -25429880846000, 18331676223750, 848074482677500, 714616060812500, -19019302889325000, 506727569992188500
Offset: 0
A(x) = 1 + 10*x + 30*x^2 - 300*x^3 - 3850*x^4 - 13940*x^5 + ... is the g.f.
-
I:=[10,30,-300,-3850,-13940,56300]; [1] cat [n le 6 select I[n] else (2*(14*n^2-16*n+7)*Self(n-1)-20*(24*n^2- 56*n+41)*Self(n-2)+80*(64*n^2-224*n+221)*Self(n-3)-1600*(24*n^2-112*n+139)*Self(n-4)+6400*(28*n^2-164*n+245)*Self(n-5)-128000*(2*n-7)^2*Self(n-6))div n^2: n in [1..30]]; // Vincenzo Librandi, Aug 25 2016
-
a[n_] := a[n] = If[n <= 6, {1, 10, 30, -300, -3850, -13940, 56300}[[n+1]], (1/n^2)(6400(28n^2 - 164n + 245) a[n-5] - 1600(24n^2 - 112n + 139) a[n-4] + 80(64n^2 - 224n + 221) a[n-3] - 20(24n^2 - 56n + 41) a[n-2] + 2(14n^2 - 16n + 7) a[n-1] - 128000(2n - 7)^2 a[n-6])];
Table[a[n], {n, 0, 20}] (* Jean-François Alcover, Dec 16 2018 *)
-
seq(N) = {
my(a = vector(N));
a[1] = 10; a[2] = 30; a[3] = -300; a[4] = -3850; a[5] = -13940; a[6] = 56300;
for (n=7, N,
my(t1 = 2*(14*n^2 - 16*n + 7)*a[n-1] - 20*(24*n^2 - 56*n + 41)*a[n-2],
t2 = 80*(64*n^2 - 224*n + 221)*a[n-3] - 1600*(24*n^2 - 112*n + 139)*a[n-4],
t3 = 6400*(28*n^2 - 164*n + 245)*a[n-5] - 128000*(2*n-7)^2 * a[n-6]);
a[n] = (t1+t2+t3)/n^2);
concat(1,a);
};
seq(25)
Showing 1-9 of 9 results.
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