A340902 Distance from the largest prime with less than 10^n decimal digits to 10^(10^n-1).

63, 621, 6101, 11333, 59511, 172473

Offset

1,1

Comments

The prime number related to a(n) is the prime immediately preceding the prime related to A096548(n).

a(5) and a(6) appear to have been first found by Patrick De Geest.

Links

Table of n, a(n) for n=1..6.

factordb.com, 10^999 - 6101, contains primality certificate related to a(3).

factordb.com, 10^9999 - 11333, contains primality certificate related to a(4).

Henri Lifchitz, Renaud Lifchitz, 10^99999 - 59511, related to a(5).

Henri Lifchitz, Renaud Lifchitz, 10^999999 - 172473, related to a(6).

Wikipedia, Titanische Primzahl, in German.

Formula

a(n) = 10^(10^n-1) - precprime(10^(10^n-1)) = A064722(10^A002283(n)).

Example

a(4) = 11333 because 10^9999 - 11333 is the largest prime not exceeding 10^9999.
a(5) = 59511 because 10^99999 - 59511 is the largest prime not exceeding 10^99999.

Crossrefs

Cf. A033874, A096548.

Sequence in context: A179537 A184448 A228262 * A181125 A228221 A022522

Adjacent sequences: A340899 A340900 A340901 * A340903 A340904 A340905

Keyword

nonn,base,more,hard

Author

Jeppe Stig Nielsen, Jan 26 2021

Status

approved