A301914 a(n) is the least k for which A301913(n) divides 3^k+2.

1, 5, 2, 6, 16, 3, 9, 6, 23, 18, 43, 4, 60, 19, 79, 25, 68, 9, 28, 78, 32, 57, 158, 137, 75, 111, 7, 22, 69, 86, 188, 65, 85, 176, 75, 64, 18, 239, 191, 286, 116, 140, 340, 338, 257, 226, 65, 23, 51, 180, 30, 207, 201, 265, 131, 481, 94, 367, 58, 85, 79

Offset

1,2

Comments

Combined with A301913 and A301915 can be used to eliminate values of 3^k+2 from prime searches.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

A301913(1) = 5 and 5 divides 3^1+2 but not 3^0+2, so a(1)=1.
A301913(5) = 19 and 19 does not divide 3^k+2 for 0 <= k < 16, however 19 divides 3^16+2, so a(5)=16.

Maple

subs(FAIL=NULL, [seq( numtheory:-mlog(-2, 3, ithprime(i)), i=3..100)]); # Robert Israel, May 04 2018

Crossrefs

Cf. A301913, A301915.

Sequence in context: A091660 A307029 A292580 * A180706 A108399 A094772

Adjacent sequences: A301911 A301912 A301913 * A301915 A301916 A301917

Keyword

nonn

Author

Luke W. Richards, Mar 28 2018

Extensions

Corrected by Robert Israel, May 04 2018

Status

approved