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Table 10 Convolution sums and triangular numbers

From: Convolution identities for twisted Eisenstein series and twisted divisor functions

 

Convolution sum

t 8 (N)

m = 1 4 N 1 σ 1 (m) σ 1 (4Nm)

1 12 {5 σ 3 (4N)+(124N) σ 1 (4N)}

 

m = 1 2 N σ 1 (2m1) σ 1 (4N(2m1))

σ 3 (2N)

t 8 (2N1)

m = 1 4 m 4 N 1 σ 1 (m) σ 1 (4Nm)

σ 3 (2N)+ σ 3 (2N;4)

17 t 8 (N1)

m = 1 mod 4 m 2 mod 4 4 N 1 σ 1 (m) σ 1 (4Nm)

σ 3 (2N;4)

9 t 8 (N1)