A117390 Numbers k such that 1 + 1234567890*Sum_{i=1..k} 10^(10i-9) is prime.

17, 56, 1888

Offset

1,1

Comments

The first two terms are given in the linked source in "Table 42: Ten Types of 'Rare' Prime Numbers" for entry "B. Sequential prime of the type: (1234567890)n 1", which designates that 1234567890 is concatenated n times and then 1 is appended. 1888, found by PrimeForm using recurrence mode, corresponds to an 18881-digit probable prime. There are no other terms <= 3000.

There are no other terms <= 10000. - Michael S. Branicky, Nov 17 2024

Links

Table of n, a(n) for n=1..3.

R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations

Crossrefs

Sequence in context: A352282 A290763 A253417 * A141841 A146682 A146650

Adjacent sequences: A117387 A117388 A117389 * A117391 A117392 A117393

Keyword

bref,hard,more,nonn

Author

Rick L. Shepherd, May 03 2006

Status

approved