83546

Appears in sequences

• Define C(n) by the recursion C(0) = 5*i where i^2 = -1, C(n+1) = 1/(1 + C(n)), then a(n) = 5*(-1)^n/Im(C(n)) where Im(z) denotes the imaginary part of z.at n=10A069962
• Row sums of the triangle A322550.at n=33A320043
• Centered heptagonal numbers which are sphenic numbers.at n=18A360183