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A078724
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Prime(n*(n+1)/2+3).
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0
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5, 7, 13, 23, 41, 61, 89, 127, 167, 223, 271, 347, 419, 491, 593, 677, 797, 911, 1033, 1171, 1303, 1481, 1619, 1801, 1999, 2203, 2383, 2621, 2803, 3061, 3323, 3559, 3823, 4093, 4391, 4679, 4999, 5333, 5653, 5987, 6323, 6701, 7043, 7489, 7867, 8273, 8699, 9127
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| The sum of the reciprocals of the terms appears to converge.
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PROG
| (PARI) triprimes(n) = { sr = 0; for(j=1, n, x = j*(j+1)/2+2; z = prime(x); sr+=1.0/z; print1(z" "); ); print(); print(sr); }
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CROSSREFS
| Apart from initial terms, primes in third diagonal of triangle in A078721.
Sequence in context: A038901 A155006 A201474 * A191022 A155757 A027674
Adjacent sequences: A078721 A078722 A078723 * A078725 A078726 A078727
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KEYWORD
| easy,nonn
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AUTHOR
| Cino Hilliard (hillcino368(AT)gmail.com), Dec 20 2002
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