190905

Appears in sequences

• Numerator of Euler(n, 13/28).at n=4A157239
• Numbers k such that 3*k+1 divides 3^k+1.at n=7A222948
• a(n) = 5*n^4 - 6*n^2 + 1. Column 4 of A378066.at n=14A378064