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
KEYWORD
nonn
AUTHOR
STATUS
approved