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Search: id:A094454
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| A094454 |
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First of 9 consecutive primes in a 3 X 3 spiral wherein the mean of all 8 sums is prime. |
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+0
3
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| 3, 457, 563, 811, 1571, 1889, 2203, 2411, 2917, 3119, 3209, 3931, 4079, 4357, 4507, 4889, 5087, 5153, 5387, 5441, 5749, 5939, 6043, 6421, 6871, 6991, 7079, 7699, 8929, 9283, 9467, 9677, 10151, 11071, 11411, 12197, 12253, 12919, 13309, 13327, 13337
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Harvey Heinz, pattern and program
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FORMULA
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Arrange 9 consecutive primes in a 3 X 3 grid wherein IBC, HAD, GFE are the first, second, and third rows of horizontal primes. Then sum the rows horizontally, vertically, and along the two main diagonals. Total the 8 sums, divide by 8, and if the mean is integral and prime, add to the sequence.
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EXAMPLE
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a(1)=3 because 3 is the first of 9 primes arranged in a 3 X 3 grid wherein the mean of all 8 sums is 41, prime
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CROSSREFS
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Cf. A094455.
Adjacent sequences: A094451 A094452 A094453 this_sequence A094455 A094456 A094457
Sequence in context: A086207 A092052 A139999 this_sequence A054702 A140015 A045616
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KEYWORD
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easy,nonn
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AUTHOR
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Enoch Haga (Enokh(AT)comcast.net), May 05 2004
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