

A258074


Table read by rows: each row represents the constant and exponent of a Colbert number.


0



5359, 5054502, 33661, 7031232, 28433, 7830457, 27653, 9167433, 19249, 13018586, 10223, 31172165
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

Each row has two entries [k,n]. With this notation, the corresponding Colbert number is k*2^n+1.
A Colbert number is an integer with more than 1,000,000 digits that is prime and has contributed to the inprogress computational proof that 78557 is the smallest Sierpiński number (A076336).
The last number, corresponding to [10223,31172165], is currently the largest known prime that is not a Mersenne prime.
This table can only have (and is expected to have) five more rows corresponding to constants k equal to 21181, 22699, 24737, 55459, and 67607.


LINKS

Table of n, a(n) for n=1..12.
C. K. Caldwell, The Prime Glossary, Colbert Number
C. K. Caldwell, The Prime Database, 10223*2^31172165+1
W. Sierpiński, Sur un problème concernant les nombres k * 2^n + 1, Elem. Math., 15 (1960), pp. 7374.
Wikipedia, Seventeen or Bust


EXAMPLE

The table is as follows:
5359, 5054502;
33661, 7031232;
28433, 7830457;
27653, 9167433;
19249, 13018586
10223, 31172165


CROSSREFS

Cf. A076336, A064699, A064721.
Sequence in context: A206681 A203962 A145770 * A237295 A296146 A063408
Adjacent sequences: A258071 A258072 A258073 * A258075 A258076 A258077


KEYWORD

nonn,tabf,fini,more


AUTHOR

Tom Edgar, May 18 2015


EXTENSIONS

a(11)a(12) from Richard N. Smith, Jul 15 2019, following by the prime 10223*2^31172165+1 found by PrimeGrid.


STATUS

approved



