237820

Appears in sequences

• a(n) = (1)*(2 + 3 + 4 + ... + n) + (1 + 2)*(3 + 4 + 5 + ... + n) + (1 + 2 + 3)*(4 + 5 + 6 + ... + n) + ... + (1 + 2 + 3 + ... + n-1)*n.at n=22A067056
• Numbers k such that 3^k mod k = 3^k mod k^2.at n=34A125774
• Numbers k such that k^2 divides 3^k-1.at n=15A127103
• Length of period of the sequence (1^1^1^..., 2^2^2^..., 3^3^3^..., 4^4^4^..., ...) modulo n.at n=46A127699