A273822 Integers k such that k^3 + 1 is the average of two positive cubes.

27, 227, 335, 2387, 9299, 104571, 113519, 118499, 212343, 258999, 328499, 455600, 699891, 820755, 971360, 977051, 1059239, 1119723, 1193631, 1421367, 1604084, 2231999, 2794067, 4191431, 5450948, 6054611, 6769607, 7672391, 7760639, 7875035, 8091615, 9606203, 15511268

Offset: 1

Author

Altug Alkan, May 31 2016

Keywords

• nonn

Examples

			27 is a term because 27^3 + 1 = (4^3 + 34^3)/2.
		

Links

• Chai Wah Wu, Table of n, a(n) for n = 1..44

Crossrefs

Cf. A001093, A003325.

Programs

PARI

isA003325(n) = for(k=1, sqrtnint(n\2, 3), ispower(n-k^3, 3) && return(1));
lista(nn) = for(n=1, nn, if(isA003325(2*(n^3+1)), print1(n, ", ")));

Extensions

a(9)-a(12) from Giovanni Resta, Jun 01 2016

a(13)-a(33) from Chai Wah Wu, Jun 19 2016