Sébastien Tao - cp's OEIS frontend

User: Sébastien Tao

Sébastien Tao has authored 2 sequences.

A363375 Numbers k such that 3^(k-1) - 2^k is prime.

4, 6, 7, 8, 22, 32, 45, 52, 58, 60, 85, 98, 211, 290, 291, 426, 428, 712, 903, 1392, 1683, 1828, 2342, 3482, 4818, 4887, 9060, 14328, 16948, 17581, 18358, 65298, 69237, 84770, 94788

Offset: 1

Sébastien Tao, May 29 2023

a(36) > 100000. - Hugo Pfoertner, Jun 03 2023

			a(1) = 4 is in the sequence because 3^3 - 2^4 =  11 is prime.
a(2) = 6 is in the sequence because 3^5 - 2^6 = 179 is prime.

Cf. A057468, A162714, A363024.

The sequence that results from increasing all terms by 1 in A162714 is a subsequence.

Cases[Range[1, 300], k_ /; PrimeQ[3^(k - 1) - 2^k]]

a(16)-a(31) from Michael S. Branicky, May 29 2023
a(32)-a(33) from Hugo Pfoertner, May 29 2023
a(34)-a(35) from Hugo Pfoertner, Jun 02 2023

A363024 Primes of the form 3^(k-1) - 2^k.

Original entry on oeis.org

11, 179, 601, 1931, 10456158899, 617669101316651, 984770866999239144049, 2153693958571958138940251, 1570042898793851235488822819, 14130386090585813000157964091, 11972515182561981102976512358583456508049, 19088056323407826758511836230558252318494847619

Offset: 1

Sébastien Tao, May 13 2023

nonn

a(23) has 1117 digits. - Michael S. Branicky, May 26 2023

			a(1) = 3^3 - 2^4 = 27 - 16 = 11 (prime).
a(2) = 3^5 - 2^6 = 243 - 64 = 179 (prime).

Michael S. Branicky, Table of n, a(n) for n = 1..22

Prime terms in A003063.

Cf. A162714, A363375, A162715 (subsequence).

Select[Table[3^(k - 1) - 2^k, {k, 1 , 100}], PrimeQ]

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User: Sébastien Tao

A363375 Numbers k such that 3^(k-1) - 2^k is prime.

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