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Search: id:A050237
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| A050237 |
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a(n) = the smallest number m such that there are exactly n sets of consecutive primes, each of which has an arithmetic mean of m. |
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+0
3
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| 1, 2, 5, 12, 38, 30, 173, 165, 12259, 8803, 36735, 67263, 5296771, 32975, 1147233
(list; graph; listen)
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OFFSET
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0,2
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COMMENT
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First appearance of n in A122821.
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EXAMPLE
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a(4) = 38 because there are exactly four sets of consecutive primes which have means
of 38: {31,37,41,43}, {29,...,47}, {23,...,53}, and {2,...,83},
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PROGRAM
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(PARI) {a(n)= m=2; starting_index=1; k=starting_index; sum_of_primes=0; prime_count=0; sets=0; until( (prime(starting_index)>m) && (sets==n), if( (prime(starting_index)> m) || (sets>n), m++; sets=0; starting_index=1; k=starting_index); sum_of_primes=sum_of_primes+prime(k); prime_count++; mean=sum_of_primes/ prime_count; if(mean<m, k++, sum_of_primes=0; prime_count=0; starting_index++; k=starting_index; if(mean==m, sets++))); return(m)} (from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 14 2004)
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CROSSREFS
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Cf. A060863, A082431, A122821.
Sequence in context: A115277 A130221 A036782 this_sequence A050258 A051436 A054581
Adjacent sequences: A050234 A050235 A050236 this_sequence A050238 A050239 A050240
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KEYWORD
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more,nonn
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AUTHOR
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Naohiro Nomoto (n_nomoto(AT)yabumi.com), May 08 2003
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EXTENSIONS
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Edited by Don Reble (djr(AT)nk.ca), Jun 17 2003
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