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a(n) = Sum_{k=1..n-2} ( prime(n+k)/2 + prime(n-k)/2 - prime(n) ).
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%I #11 Dec 14 2024 20:38:54

%S 0,2,-1,5,4,16,17,3,24,6,9,42,50,27,10,56,40,59,119,103,130,110,50,83,

%T 167,204,302,349,102,141,130,243,103,233,225,219,287,282,277,437,273,

%U 438,524,700,428,148,236,427,532,548,772,580,598,614,628,864,884,1018,1274,1053

%N a(n) = Sum_{k=1..n-2} ( prime(n+k)/2 + prime(n-k)/2 - prime(n) ).

%p A124660 := proc(n) add( (ithprime(n+k)+ithprime(n-k))/2-ithprime(n), k=1..n-2) ; end proc:

%p seq(A124660(n),n=3..80) ; # _R. J. Mathar_, Mar 28 2010

%t Table[Sum[Prime[n+k]/2+Prime[n-k]/2-Prime[n],{k,n-2}],{n,3,62}] (* _James C. McMahon_, Dec 14 2024 *)

%K sign,easy

%O 3,2

%A _Artur Jasinski_, Dec 23 2006

%E Offset corrected and sequence extended by _R. J. Mathar_, Mar 28 2010