A301919 - OEIS

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A301919

a(n) is the least value of k for which A301918(n) divides 3^k+3.

0, 1, 3, 4, 9, 10, 15, 16, 10, 5, 22, 27, 6, 12, 7, 40, 45, 25, 51, 18, 57, 64, 69, 70, 75, 26, 40, 82, 87, 9, 99, 100, 106, 112, 117, 61, 129, 135, 16, 141, 142, 147, 18, 159, 166, 85, 88, 177, 62, 94, 190, 195, 100, 201, 103, 74, 225, 115, 231, 232, 244, 84

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OFFSET

1,3

COMMENTS

This can be used to identify P+1 values to primality test potential primes P of the form 3^k+2, i.e., A051783.

LINKS

Table of n, a(n) for n=1..62.

FORMULA

a(n) = A301917(n-1) + 1 for n > 2.

EXAMPLE

All values of 3^k+3 are multiples of 2, so 3^0+3 = 4 is the least value of k which is a multiple of 2.

a(10) = 5 and A301918(10) = 41 so 3^5+3 = 246 is the first multiple of 41 which can be written in the form 3^k+3.