A014121 Numbers of form |2^i - 3^j|.

0, 1, 2, 3, 5, 7, 8, 11, 13, 15, 17, 19, 23, 25, 26, 29, 31, 37, 47, 49, 55, 61, 63, 65, 73, 77, 79, 80, 101, 115, 119, 125, 127, 139, 175, 179, 211, 217, 227, 229, 235, 239, 241, 242, 247, 253, 255, 269, 295, 431, 473, 485, 503, 509, 511, 601, 665, 697, 713, 721, 725, 727, 728, 781, 943, 997

Offset: 1

Author

Richard C. Schroeppel

Keywords

• nonn

Comments

A128760(a(n)) > 0. - Reinhard Zumkeller, Mar 25 2007

One can establish if a given integer m is a term by computing all integral points on elliptic curves u*x^3 - v*y^2 = +-m for all u in {1,2,4} and v in {1, 3} and identifying if for any point x is a power of 2 while y is a power of 3. - Max Alekseyev, Jun 17 2025

Links

• Kevin Ryde, Conjectured table of n, a(n) for n = 1..3000
• Kevin Ryde, PARI/GP Code
• Terence Tao, Hilbert's seventh problem, and powers of 2 and 3
• Ralf Stephan, PARI/GP code to check for absent values.

Programs

PARI

\\ See links.

Extensions

More terms from Max Alekseyev, Nov 16 2012