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!)
A025019 Smallest prime in Goldbach partition of A025018(n). 14
2, 3, 5, 7, 19, 23, 31, 47, 73, 103, 139, 173, 211, 233, 293, 313, 331, 359, 383, 389, 523, 601, 727, 751, 829, 929, 997, 1039, 1093, 1163, 1321, 1427, 1583, 1789, 1861, 1877, 1879, 2029, 2089, 2803, 3061, 3163, 3457, 3463, 3529, 3613, 3769, 3917, 4003, 4027, 4057 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Increasing subsequence of A020481.
For n > 2, a(n) ~ (log(A025018(n)))^e/e, while an upper bound could be written as UB(a(n)) = floor(log(A025018(n)))^e/2 (therefore, for any even v such that 12 <= v <= A025018(67) UB is true). It looks that both approximation and UB are true for any n > 2. Assuming the second equation to be true, UB(10^80) = 718967, UB(10^500) = 104745517, etc. - Sergey Pavlov, Jan 17 2021
LINKS
N. J. A. Sloane, Table of n, a(n) for n=1..67 (from the web page of Tomás Oliveira e Silva)
Mark A. Herkommer, Goldbach Conjecture Research
Tomás Oliveira e Silva, Goldbach conjecture verification
Jörg Richstein, Verifying the Goldbach conjecture up to 4 * 10^14, Math. Comp., 70 (2001), 1745-1749.
EXAMPLE
1427 and 1583 are two consecutive terms because A020481(167535419) = 1427 and A020481(209955962) = 1583 and for 167535419 < n < 209955962 A020481(n) <= 1427.
MATHEMATICA
p = 1; q = {}; Do[ k = 2; While[ !PrimeQ[k] || !PrimeQ[2n - k], k++ ]; If[k > p, p = k; q = Append[q, p]], {n, 2, 10^8}]; q
CROSSREFS
Sequence in context: A244529 A332583 A345335 * A140327 A346167 A163074
KEYWORD
nonn
AUTHOR
David W. Wilson, Dec 11 1999
EXTENSIONS
Edited and extended by Robert G. Wilson v, Dec 13 2002
More terms and b-file added by N. J. A. Sloane, Nov 28 2007
STATUS
approved

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 12 14:01 EDT 2024. Contains 371635 sequences. (Running on oeis4.)