login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A115333 Sum of primes that do not divide n and are less than the largest prime dividing n. 0

%I #15 Mar 14 2015 18:34:49

%S 0,0,2,0,5,0,10,0,2,3,17,0,28,8,2,0,41,0,58,3,7,15,77,0,5,26,2,8,100,

%T 0,129,0,14,39,5,0,160,56,25,3,197,5,238,15,2,75,281,0,10,3,38,26,328,

%U 0,12,8,55,98,381,0,440,127,7,0,23,12,501,39,74,3,568,0,639,158,2,56,10

%N Sum of primes that do not divide n and are less than the largest prime dividing n.

%C When n is prime, n = largest prime dividing n; hence a(n) is the sum of all primes less than n = A034387(n)-n. a(n) = SUM{p such that p is in A000040 AND NOT(p|n) AND p < A006530(n)}. - _Jonathan Vos Post_, Mar 08 2006

%C The zeros give A055932: All prime divisors are consecutive primes starting at 2. - _Robert G. Wilson v_, May 01 2006

%e The primes < 7 and coprime to 7 are 2, 3 and 5. So a(7) = 2+3+5 = 10.

%t f[n_] := Plus @@ Complement[Prime@ Range@ PrimePi[ Max[First /@ FactorInteger@n] - 1], First /@ FactorInteger@n]; Array[f, 77] (* _Hans Havermann_, Mar 06 2006 *)

%Y Cf. A000040, A006530, A034387, A066911, A083720.

%K nonn

%O 1,3

%A _Leroy Quet_, Mar 05 2006

%E More terms from _Hans Havermann_, Mar 06 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 24 18:05 EDT 2024. Contains 371962 sequences. (Running on oeis4.)