A282017 Coefficients in q-expansion of (E_4 + E_2^2)/2, where E_2 and E_4 are the Eisenstein series shown in A006352 and A004009, respectively.

1, 96, 1296, 4992, 13488, 25920, 50112, 74496, 123120, 164832, 246240, 300672, 442176, 501312, 694656, 794880, 1052016, 1135296, 1534032, 1591680, 2086560, 2214912, 2763072, 2840832, 3723840, 3668640, 4590432, 4750080, 5801088, 5728320, 7309440, 7007232, 8697456, 8722944, 10349856, 10160640

Offset

0,2

Links

Table of n, a(n) for n=0..35.

Maple

with(numtheory); M:=100;
E := proc(k) local n, t1; global M;
t1 := 1-(2*k/bernoulli(k))*add(sigma[k-1](n)*q^n, n=1..M+1);
series(t1, q, M+1); end;
e2:=E(2); e4:=E(4); e6:=E(6);
series((e2^2+e4)/2, q, M+1);
seriestolist(%);

Crossrefs

Cf. A004009 and A006352.

Sequence in context: A232918 A187165 A229533 * A263567 A223292 A168526

Adjacent sequences: A282014 A282015 A282016 * A282018 A282019 A282020

Keyword

nonn

Author

N. J. A. Sloane, Feb 05 2017

Status

approved