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A138980
a(0)=1; for n>=1, a(n) = smallest prime > a(n-1) such that (sum{k=0 to n} a(k)) is composite.
3
1, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281
OFFSET
0,2
COMMENTS
Although superficially similar to A049561, the two sequences are in fact quite different (see for example A138982).
LINKS
R. J. Mathar, Apr 30 2008, Table of n, a(n) for n = 0..112
MAPLE
A138980 := proc(n) option remember ; local i, p ; if n = 0 then 1 ; else for p from nextprime(A138980(n-1)) do if isprime(p) then if not isprime( p+add(A138980(i), i=0..n-1) ) then RETURN(p) ; fi ; fi ; od: fi ; end: seq(A138980(n), n=0..120) ; # R. J. Mathar Apr 30 2008
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Apr 05 2008
EXTENSIONS
More terms from R. J. Mathar, Apr 30 2008
STATUS
approved