A078131 Numbers which can be written as sum of cubes > 1.

8, 16, 24, 27, 32, 35, 40, 43, 48, 51, 54, 56, 59, 62, 64, 67, 70, 72, 75, 78, 80, 81, 83, 86, 88, 89, 91, 94, 96, 97, 99, 102, 104, 105, 107, 108, 110, 112, 113, 115, 116, 118, 120, 121, 123, 124, 125, 126, 128, 129, 131, 132, 133, 134, 135, 136, 137, 139, 140

Offset: 1

Author

Reinhard Zumkeller, Nov 19 2002

Keywords

• nonn

Comments

A078128(a(n)) > 0.

Examples

			35 is in the sequence because 35 = 27 + 8.
		

Links

• Eric Weisstein's World of Mathematics, Cubic Number.
• Index entries for sequences related to sums of cubes

Crossrefs

Cf. A000578, A078129 (complement of this sequence), A078130, A078137.

Programs

Maple

a:=proc(n) local h, hser: h:=1/product(1-x^(j^3),j=2..30): hser:=series(h,x=0,150): if coeff(hser,x^n)>0 then n else fi end: seq(a(n),n=1..140); # Emeric Deutsch, Mar 30 2006

Mathematica

terms = 60;
(Exponent[#, x]& /@ List @@ Normal[1/Product[1-x^j^3, {j, 2, Ceiling[(3 terms)^(1/3)]}] + O[x]^(3 terms)])[[2 ;; terms+1]] (* Jean-François Alcover, Aug 04 2018, after Emeric Deutsch *)

Formula

a(n) = n + 83 for n >= 72. - Robert Israel, Apr 05 2020