

A138855


Halfsum (or average) of cubes of two distinct odd primes.


1



76, 185, 234, 679, 728, 837, 1112, 1161, 1270, 1764, 2470, 2519, 2628, 3122, 3443, 3492, 3555, 3601, 4095, 4528, 5886, 6097, 6146, 6255, 6749, 7182, 8540, 9513, 12208, 12257, 12366, 12860, 13293, 14651, 14909, 14958, 15067, 15561, 15624, 15994
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OFFSET

1,1


COMMENTS

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


LINKS



FORMULA

A138855 = { ( prime(i)^3+prime(j)^3 )/2 ; i>j>1 } = (1/2) { even terms in A120398 } = { even terms in A138854 } / 2  4.


MATHEMATICA

With[{nn=40}, Take[Union[Mean/@(Subsets[Prime[Range[2, nn/2]], {2}]^3)], nn]] (* Harvey P. Dale, Nov 16 2013 *)


PROG

(PARI) for(n=1, 10^5, isA120398(2*n) & print1(n", "))


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



