A083714 (greatest prime <= n) - (greatest prime factor of n).

0, 0, 0, 1, 0, 2, 0, 5, 4, 2, 0, 8, 0, 6, 8, 11, 0, 14, 0, 14, 12, 8, 0, 20, 18, 10, 20, 16, 0, 24, 0, 29, 20, 14, 24, 28, 0, 18, 24, 32, 0, 34, 0, 32, 38, 20, 0, 44, 40, 42, 30, 34, 0, 50, 42, 46, 34, 24, 0, 54, 0, 30, 54, 59, 48, 50, 0, 50, 44, 60, 0, 68, 0, 36, 68, 54, 62, 60, 0, 74

Offset

1,6

Comments

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

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

Links

Table of n, a(n) for n=1..80.

Mathematica

Join[{0}, Table[NextPrime[n+1, -1]-FactorInteger[n][[-1, 1]], {n, 2, 90}]] (* Harvey P. Dale, Nov 27 2011 *)

Crossrefs

Cf. A083718, A083715, A083716, A083717.

Sequence in context: A164976 A261745 A378979 * A215481 A262933 A197253

Adjacent sequences: A083711 A083712 A083713 * A083715 A083716 A083717

Keyword

nonn

Author

Reinhard Zumkeller, May 04 2003

Status

approved