|
%I #14 Jul 04 2018 14:18:23
%S 1,2,5,12,38,30,173,165,12259,8803,36735,67263,5296771,32975,1147233
%N 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.
%C First appearance of n in A122821.
%e 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},
%o (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)} \\ _Rick L. Shepherd_, Jun 14 2004
%Y Cf. A060863, A082431, A122821.
%K more,nonn
%O 0,2
%A _Naohiro Nomoto_, May 08 2003
%E Edited by _Don Reble_, Jun 17 2003
|
