A337426 -id:A337426 - cp's OEIS frontend

A337423 a(n) is the least prime of the form (3^j*5^k - 1)/2, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

7, 37, 67, 337, 607, 3037, 15187, 27337, 49207, 683437, 0, 131835937, 659179687, 19929037, 35872267, 228881835937, 2491129687, 0, 0, 311391210937, 12013549804687, 0, 235357947067, 1176789735337, 0, 10591107618037, 52955538090187, 5675104819335937, 608185958862304687

Offset: 2

Hugo Pfoertner, Aug 27 2020

nonn

Cf. A093625, A076481, A337424, A337425, A337426.

A337425 a(n) is the least prime of the form (3^j*5^k + 1)/2, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

Original entry on oeis.org

0, 23, 113, 563, 1013, 1823, 70313, 351563, 82013, 410063, 43945313, 1328603, 18452813, 1977539063, 0, 830376563, 538084013, 968551223, 13452100313, 1441625976563, 43584805013, 2145767211914063, 0, 0, 9806581127813, 6354664570823, 681012578320313, 441296150751563, 0

Offset: 2

Hugo Pfoertner, Aug 27 2020

nonn

Cf. A093625, A076481, A337423, A337424, A337426.

A337424 Sums s of positive exponents such that no prime of the form (3^j*5^k - 1)/2 with j + k = s exists.

Original entry on oeis.org

12, 19, 20, 23, 26, 33, 34, 35, 40, 41, 48, 51, 52, 54, 63, 68, 69, 74, 75, 78, 83, 87, 93, 97, 101, 103, 105, 114, 116, 123, 132, 135, 138, 141, 142, 144, 147, 152, 154, 159, 165, 170, 172, 173, 179, 180, 186, 187, 189, 192, 194, 202, 203, 210, 215, 216, 217, 218, 221

Offset: 1

Hugo Pfoertner, Aug 27 2020

nonn

Positions of 0 in A337423.

Cf. A336772, A337426.

cp's OEIS Frontend

A337423 a(n) is the least prime of the form (3^j*5^k - 1)/2, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

Views

Author

Keywords

Crossrefs

A337425 a(n) is the least prime of the form (3^j*5^k + 1)/2, j > 0, k > 0, j + k = n. a(n) = 0 if no such prime exists.

Views

Author

Keywords

Crossrefs

A337424 Sums s of positive exponents such that no prime of the form (3^j*5^k - 1)/2 with j + k = s exists.

Views

Author

Keywords

Crossrefs