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A053845
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Primes of form prime(1) + ... + prime(k) + 1.
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3
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3, 11, 29, 59, 101, 239, 569, 1061, 1481, 1721, 4889, 5351, 6871, 22549, 23593, 25801, 29297, 35569, 38239, 41023, 71209, 77137, 87517, 94057, 105541, 120349, 122921, 125509, 128113, 133387, 138869, 141677, 156109, 159073, 165041, 183707
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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prime(1) + 1 = 2 + 1 = 3 (prime, thus a(1));
prime(1) + prime(2) + 1 = 2 + 3 + 1 = 6 (nonprime);
prime(1) + prime(2) + prime(3) + 1 = 2 + 3 + 5 + 1 = 11 (prime, thus a(2)); etc. - Jon E. Schoenfield, Jan 09 2015
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MATHEMATICA
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PROG
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(UBASIC) 10 x=x+1; 20 if x<>prmdiv(x) then 10; 30 y=x; 40 r=r+y; 50 if r=prmdiv(r) then print r; :p=p+1; 60 if p<100 then 10
(PARI) lista(nn) = {s = 1; for (n=1, nn, s += prime(n); if (isprime(s), print1(s, ", ")); ); } \\ Michel Marcus, Jan 10 2015
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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