A186732 Closest prime to 3^n (in case of a tie, choose the smaller prime).

3, 7, 29, 79, 241, 727, 2179, 6563, 19681, 59051, 177131, 531457, 1594331, 4782971, 14348909, 43046747, 129140153, 387420479, 1162261453, 3486784393, 10460353199, 31381059607, 94143178807, 282429536483, 847288609457

Offset

1,1

Comments

Nearest prime program by Ignacio Grande in LinkedIn Mathematica users group as answer to my question. 83 is why the 4th term is called "lowest" or "smallest" for a dual prime near 3^4.

Links

Table of n, a(n) for n=1..25.

Mathematica

f[n_] := Block[{m = 3^n}, Min@ Nearest[ Select[{NextPrime[m, -1], m, NextPrime[m]}, PrimeQ], m]]; Array[f, 25] (* Robert G. Wilson v, Jan 21 2012 *)

Crossrefs

Sequence in context: A148759 A148760 A148761 * A148762 A096064 A148763

Adjacent sequences: A186729 A186730 A186731 * A186733 A186734 A186735

Keyword

nonn,easy

Author

Roger L. Bagula, Jan 21 2012

Extensions

a(16)-a(25) from Robert G. Wilson v, Jan 21 2012

Status

approved