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A341631 Numbers k such that A073837(k) is prime. 2
2, 7, 9, 14, 19, 27, 28, 29, 30, 36, 44, 60, 61, 68, 70, 71, 87, 88, 89, 100, 101, 104, 105, 108, 109, 112, 113, 138, 157, 174, 192, 193, 199, 201, 202, 203, 204, 210, 274, 275, 276, 277, 304, 305, 306, 364, 365, 366, 372, 373, 384, 387, 388, 389, 399, 400, 401, 405, 471, 472, 473, 511, 512, 513 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
Numbers k such that the sum of primes from k to 2*k is prime.
LINKS
EXAMPLE
a(3) = 9 is in the sequence because A073837(9) = 11+13+17 = 41 is prime.
MAPLE
R:= 2: S:= [2, 3]: s:= 5: q:= 5: count:= 1:
for n from 3 while count < 100 do
if n = S[1]+1 then S:= S[2..-1]; s:= s-n+1 fi;
if q <= 2*n then S:= [op(S), q]; s:= s+q; q:= nextprime(q) fi;
if isprime(s) then count:= count+1; R:= R, n; fi;
od:
R;
CROSSREFS
Sequence in context: A184400 A074244 A190565 * A102994 A226824 A168132
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Feb 16 2021
STATUS
approved

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Last modified July 18 10:00 EDT 2024. Contains 374378 sequences. (Running on oeis4.)