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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 in-progress 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. 73-74.

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

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Last modified May 29 10:41 EDT 2020. Contains 334699 sequences. (Running on oeis4.)