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Average of smallest prime greater than n^2 and largest prime less than (n+1)^2.
4

%I #8 May 10 2019 17:50:07

%S 6,12,20,30,42,57,73,90,107,133,158,183,210,239,270,305,345,382,420,

%T 461,505,556,598,652,702,753,813,870,930,994,1059,1122,1193,1260,1332,

%U 1406,1479,1560,1635,1726,1812,1897,1983,2070,2168,2255,2354,2444

%N Average of smallest prime greater than n^2 and largest prime less than (n+1)^2.

%C a(1)=2.5 which is not an integer

%H Harvey P. Dale, <a href="/A056930/b056930.txt">Table of n, a(n) for n = 2..1000</a>

%F a(n) =(A007491(n)+A053001(n+1))/2 =A002378(n)-A056931(n)

%e a(4)=1 because smallest prime greater than 4^2 is 17, largest prime less than 5^2 is 23 and average of 17 and 23 is 20

%t Table[Mean[{NextPrime[n^2],NextPrime[(n+1)^2,-1]}],{n,2,50}] (* _Harvey P. Dale_, May 10 2019 *)

%Y Cf. A002378, A007491, A053000, A053001, A056927, A056928, A056929, A056931.

%K easy,nonn

%O 2,1

%A _Henry Bottomley_, Jul 12 2000