A175320 - OEIS

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A175320

Positive integers which cannot be represented as half-sums (averages) of two primes with indices that are primes with prime indices.

1, 2, 3, 4, 6, 7, 9, 10, 12, 13, 14, 15, 16, 17, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, 33, 34, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 61, 62, 63, 64, 65, 67, 68, 70, 71, 72, 73, 74, 75, 76, 77, 78, 80, 81, 82, 83, 84, 85

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Appears to be finite with the last term being a(1578727)=161352166. If a(1578728) exists, it is greater than 10^9.

The (apparently) last 19 terms are listed in A175321.

Computed at the suggestion of Jonathan Vos Post.

LINKS

J. S. Kimberley, Table of n, a(n) for n=1..1578727

FORMULA

The complement of A175319.

CROSSREFS