Voozh

A342834

a(n) is the number whose decimal expansion consists of the concatenation of the largest 1-digit prime = 7, the largest 2-digit prime = 97, ... up to the largest n-digit prime = A003618(n).

7, 797, 797997, 7979979973, 797997997399991, 797997997399991999983, 7979979973999919999839999991, 797997997399991999983999999199999989, 797997997399991999983999999199999989999999937, 7979979973999919999839999991999999899999999379999999967

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(n) has n*(n+1)/2 digits.

a(1) = 7 and a(2) = 797, these are only 2 known indices for which a(n) = A338968(n).

The decimal expansion of the limit when n -> oo of a(n) is A340220.

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

The greatest primes with 1, 2 and 3 digits are respectively 7, 97 and 997, hence, a(3) = 7||97||997 = 797997 where || stands for concatenation.

PROG