

A155215


a(n) is the average of the smallest prime greater than n and largest prime smaller than n + prime(n).


1



2, 3, 6, 6, 10, 12, 17, 17, 21, 24, 27, 30, 35, 35, 39, 42, 46, 46, 53, 56, 56, 60, 66, 69, 71, 71, 78, 80, 84, 85, 97, 97, 102, 102, 109, 109, 117, 120, 120, 126, 127, 127, 140, 140, 144, 144, 155, 161, 162, 165, 168, 168, 176, 176, 185, 188, 188, 188, 196
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OFFSET

1,1


LINKS



EXAMPLE

a(32)= 97. Smallest prime greater than 32 is 37 and p(32)=131, largest prime smaller than 32+p(32) or 163 is 157. So (37+157)/2 = 97


MATHEMATICA

Table[(NextPrime[n]+NextPrime[n+Prime[n], 1])/2, {n, 100}] (* Harvey P. Dale, Apr 17 2013 *)


CROSSREFS



KEYWORD

nonn


AUTHOR

Avik Roy (avik_3.1416(AT)yahoo.co.in), Jan 22 2009


EXTENSIONS



STATUS

approved



