cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A138855 Half-sum (or average) of cubes of two distinct odd primes.

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%I A138855 #10 Nov 30 2015 21:26:55
%S A138855 76,185,234,679,728,837,1112,1161,1270,1764,2470,2519,2628,3122,3443,
%T A138855 3492,3555,3601,4095,4528,5886,6097,6146,6255,6749,7182,8540,9513,
%U A138855 12208,12257,12366,12860,13293,14651,14909,14958,15067,15561,15624,15994
%N A138855 Half-sum (or average) of cubes of two distinct odd primes.
%C A138855 Even terms of A120398, divided by two. (Terms in A120398 are even iff they are the sum of two odd prime cubes.) Also, even terms of A138854 divided by two minus 4
%H A138855 <a href="/index/Su#ssq">Index to sequences related to sums of cubes</a>.
%F A138855 A138855 = { ( prime(i)^3+prime(j)^3 )/2 ; i>j>1 } = (1/2) { even terms in A120398 } = { even terms in A138854 } / 2 - 4.
%t A138855 With[{nn=40},Take[Union[Mean/@(Subsets[Prime[Range[2,nn/2]],{2}]^3)],nn]] (* _Harvey P. Dale_, Nov 16 2013 *)
%o A138855 (PARI) for(n=1,10^5, isA120398(2*n) & print1(n", "))
%Y A138855 Cf. A120398, A138854.
%K A138855 nonn
%O A138855 1,1
%A A138855 _M. F. Hasler_, Apr 13 2008