This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A007414 Largest number not a sum of distinct primes >= prime(n). (Formerly M4080) 2
 6, 9, 27, 45, 45, 57, 75, 81, 87, 105, 123, 135, 135, 165, 169, 189, 195, 209, 231, 237, 267, 267, 267, 315, 315, 333, 345, 363, 369, 405, 411, 429, 441, 465, 483, 485, 525, 525, 535, 555, 579, 579, 609, 611, 645, 657, 687, 705, 715, 717, 721 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Kløve conjectures that a(n) ~ 3p where p is the n-th prime. This implies the (binary) Goldbach conjecture for large enough n. - Charles R Greathouse IV, Apr 03 2012 REFERENCES Torleiv Kløve, Sums of distinct primes. Nordisk Mat. Tidskr. 21 (1973), pp. 138-140. J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 73. N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 PROG (PARI) issum(n, x)=if(isprime(n), return(n>=x)); if(if(n%2, n<3*x, n<2*x), return(!n)); forprime(p=x, n-if(n%2, 2*x, x), if(issum(n-p, p+1), return(1))); 0 a(n)=my(p=prime(n), k=2*p-2, lower=k, upper=2*k+2); while(upper>lower, if(issum(upper, p), upper--, lower=2*k+2; k=upper; upper=2*k+2)); k \\ Charles R Greathouse IV, Apr 03 2012 CROSSREFS Cf. A180306. Sequence in context: A243708 A300345 A024878 * A274977 A025493 A091519 Adjacent sequences:  A007411 A007412 A007413 * A007415 A007416 A007417 KEYWORD nonn AUTHOR 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 January 23 02:34 EST 2019. Contains 319365 sequences. (Running on oeis4.)