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A239716 Primes of the form m = 6^i + 6^j - 1, where i > j >= 0. 1
41, 251, 1301, 1511, 46691, 47951, 279941, 1679831, 10077911, 10124351, 60466181, 60466391, 60473951, 362797091, 362797271, 362843711, 2176782371, 2237248511, 13060694051, 13121160191, 78364164101, 78364164311, 78364171871 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The base-6 representation of a term 6^i + 6^j - 1 has base-6 digital sum = 1 + 5*j == 1 (mod 5).

In base-6 representation the first terms are 105, 1055, 10005, 10555, 1000055, 1005555, 10000005, 100000555, 1000000555, 1000555555, 10000000005, 10000000555,

LINKS

Hieronymus Fischer, Table of n, a(n) for n = 1..60

EXAMPLE

a(1) = 41, since 41 = 6^2 + 6^1 - 1 is prime.

a(2) = 251, since 251 = 6^3 + 6^2 - 1 is prime.

PROG

(Smalltalk)

A239716

  "Answers an array of the first n terms of A239716.

  Uses method primesWhichAreDistinctPowersOf: b withOffset: d from A239712.

  Usage: n A239716

  Answer: #(41 241 ... ) [a(1) ... a(n)]"

  ^self primesWhichAreDistinctPowersOf: 6 withOffset: -1

CROSSREFS

Sequence in context: A140634 A140848 A063939 * A275180 A275128 A142113

Adjacent sequences:  A239713 A239714 A239715 * A239717 A239718 A239719

KEYWORD

nonn

AUTHOR

Hieronymus Fischer, Apr 14 2014

STATUS

approved

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Last modified September 22 00:42 EDT 2020. Contains 337276 sequences. (Running on oeis4.)