The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A066285 a(n) is the minimal difference between primes p and q whose sum is 2n. 6
 0, 0, 2, 0, 2, 0, 6, 4, 6, 0, 2, 0, 6, 4, 6, 0, 2, 0, 6, 4, 18, 0, 10, 12, 6, 8, 18, 0, 2, 0, 18, 8, 6, 12, 10, 0, 18, 4, 6, 0, 2, 0, 6, 4, 30, 0, 10, 24, 6, 16, 18, 0, 14, 24, 6, 8, 30, 0, 2, 0, 18, 8, 6, 12, 10, 0, 30, 4, 6, 0, 2, 0, 30, 8, 6, 12, 10, 0, 18, 4, 30, 0, 10, 24, 6, 28, 18, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,3 COMMENTS Terms are always even numbers because primes present in Goldbach partitions of n > 4 are odd and n = 4 has just one partition (2+2) where the difference is 0. a(n) = 0 iff n is prime. - Marcin Barylski, Apr 28 2018 LINKS FORMULA a(n) = 2 * A047160(n). - Alois P. Heinz, Jun 01 2020 MATHEMATICA a[n_] := For[p=n, True, p--, If[PrimeQ[p]&&PrimeQ[2n-p], Return[2n-2p]]] PROG (PARI) a(n) = {forstep(k=n, 1, -1, if (isprime(k) && isprime(2*n-k), return(2*n-2*k)); ); } \\ Michel Marcus, Jun 01 2020 CROSSREFS Cf. A002372, A047160, A065978, A066286, A303603. Sequence in context: A136581 A175950 A339423 * A327873 A136665 A047765 Adjacent sequences:  A066282 A066283 A066284 * A066286 A066287 A066288 KEYWORD nonn,easy AUTHOR Dean Hickerson, Dec 12 2001 STATUS approved

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

Last modified July 30 07:18 EDT 2021. Contains 346348 sequences. (Running on oeis4.)