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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A160358 Indices of primes in A133547, i.e., numbers n such that the sum of the squares of the first n odd primes is prime.

Original entry on oeis.org

3, 5, 9, 11, 23, 29, 63, 65, 71, 95, 141, 159, 161, 173, 179, 183, 209, 219, 255, 299, 323, 341, 365, 371, 389, 393, 453, 485, 521, 567, 579, 605, 623, 633, 635, 639, 677, 701, 711, 723, 725, 747, 785, 827, 867, 945, 981, 993, 999, 1001, 1013, 1035, 1037, 1041
Offset: 1

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Author

M. F. Hasler, May 18 2009

Keywords

Comments

All terms are necessarily odd. Thus one could also consider the sequence floor(a(n)/2) = (1,2,4,5,11,14,31,32,35,...). Other possible variations would be to list the index a(n)+1 of the largest prime in that sum, or, since this is always even, (a(n)+1)/2 = (2,3,5,6,12,15,32,33,36,...).

Crossrefs

Cf. A098561, A133547.

Programs

  • PARI
    s=0; for( i=2,1999, isprime(s+=prime(i)^2) & print1(i-1,","))

Formula

A160359(n) = A133547(a(n)) = A024450(a(n)+1) - 4.
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