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A138853 Numbers which are the sum of 3 cubes of distinct odd primes. 4
495, 1483, 1701, 1799, 2349, 2567, 2665, 3555, 3653, 3871, 5065, 5283, 5381, 6271, 6369, 6587, 7011, 7137, 7229, 7235, 7327, 7453, 8217, 8315, 8441, 8533, 9083, 9181, 9399, 10387, 11799, 11897, 12115, 12319, 12537, 12635, 13103, 13525, 13623, 13841 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Dropping the restriction to odd primes would add to this sequence of odd terms the sequence of even terms of the form 8+p(i)^3+p(j)^3 (i>j>1), i.e. 8+{ even terms of A120398 }, cf. A138854.

LINKS

Chai Wah Wu, Table of n, a(n) for n = 1..10000 (terms 1..560 from R. J. Mathar)

Index to sequences related to sums of cubes.

FORMULA

A138853={ p(i)^3+p(j)^3+p(k)^3 ; i>j>k>1 }

PROG

(PARI) isA138853(n)= local( c, d); n>494 && forprime( p=floor( sqrtn( n\3+1, 3))+1, floor( sqrtn( n-151, 3)), d=n-p^3; forprime( q=floor( sqrtn( d\2+1, 3))+1, min( p-1, floor( sqrtn( d-26, 3))), round( sqrtn( c=d-q^3, 3 ))^3==c || next; isprime( round( sqrtn( c, 3 ))) && return(1)))

forstep(n=3^3+5^3+7^3, 10^5, 2, isA138853(n)&print1(n", "))

CROSSREFS

Cf. A024975 (a^3+b^3+c^3, a>b>c>0), A138854, A120398.

Sequence in context: A059828 A160851 A031898 * A164716 A164718 A151965

Adjacent sequences:  A138850 A138851 A138852 * A138854 A138855 A138856

KEYWORD

nonn

AUTHOR

M. F. Hasler, Apr 13 2008

STATUS

approved

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Last modified July 23 22:27 EDT 2017. Contains 289716 sequences.