A069353 Numbers of form 2^i*3^j - 1 with i, j >= 0.

0, 1, 2, 3, 5, 7, 8, 11, 15, 17, 23, 26, 31, 35, 47, 53, 63, 71, 80, 95, 107, 127, 143, 161, 191, 215, 242, 255, 287, 323, 383, 431, 485, 511, 575, 647, 728, 767, 863, 971, 1023, 1151, 1295, 1457, 1535, 1727, 1943, 2047, 2186, 2303, 2591, 2915, 3071, 3455, 3887

Offset

1,3

Comments

Are there infinitely many primes in this sequence? See A005105.

If m is a term then also 2*m + 1 and 3*m + 2.

Links

Table of n, a(n) for n=1..55.

Graham Everest, Peter Rogers, and Thomas Ward, A higher-rank Mersenne problem, Algorithmic Number Theory: 5th International Symposium, ANTS-V Sydney, Australia, July 7-12, 2002 Proceedings 5, Lect. Notes Computer Sci. 2369, Springer Berlin Heidelberg, 2002, pp. 95-107.

Formula

a(n) = A003586(n)-1.

Mathematica

With[{max = 4000}, Sort[Flatten[Table[2^i*3^j - 1, {i, 0, Log2[max]}, {j, 0, Log[3, max/2^i]}]]]] (* Amiram Eldar, Jul 13 2023 *)

Crossrefs

Cf. A003586, A055600, A069355, A005105.

Sequence in context: A278591 A191121 A026401 * A300163 A352204 A224858

Adjacent sequences: A069350 A069351 A069352 * A069354 A069355 A069356

Keyword

nonn

Author

Reinhard Zumkeller, Mar 18 2002

Status

approved