A083715 (greatest prime <= n) mod (greatest prime factor of n).

0, 0, 0, 1, 0, 2, 0, 1, 1, 2, 0, 2, 0, 6, 3, 1, 0, 2, 0, 4, 5, 8, 0, 2, 3, 10, 2, 2, 0, 4, 0, 1, 9, 14, 3, 1, 0, 18, 11, 2, 0, 6, 0, 10, 3, 20, 0, 2, 5, 2, 13, 8, 0, 2, 9, 4, 15, 24, 0, 4, 0, 30, 5, 1, 9, 6, 0, 16, 21, 4, 0, 2, 0, 36, 3, 16, 7, 8, 0, 4, 1, 38, 0, 6, 15, 40, 25, 6, 0, 4, 11, 20, 27, 42

Offset: 1

Author

Reinhard Zumkeller, May 04 2003

Keywords

• nonn

Comments

a(n) = A007917(n) mod A006530(n);

n>1: a(n) = 0 iff n is prime.

Crossrefs

Cf. A083716, A083717, A083714, A083718.