|
| |
|
|
A101078
|
|
Indices of primes in sequence defined by A(0) = 89, A(n) = 10*A(n-1) - 11 for n > 0.
|
|
0
| |
|
|
0, 2, 5, 30, 35, 60, 116, 228, 338, 3164, 3957, 5276, 5342, 6078, 6534, 8484
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Numbers n such that (790*10^n + 11)/9 is prime.
Numbers n such that digit 8 followed by n >= 0 occurrences of digit 7 followed by digit 9 is prime.
Numbers corresponding to terms <= 338 are certified primes.
|
|
|
REFERENCES
| Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
|
|
|
LINKS
| Makoto Kamada, Factorizations of near-repdigit numbers.
|
|
|
EXAMPLE
| 8777779 is prime, hence 5 is a term.
|
|
|
PROG
| (PARI) a=89; for(n=0, 1000, if(isprime(a), print1(n, ", ")); a=10*a-11)
(PARI) for(n=0, 1000, if(isprime((790*10^n+11)/9), print1(n, ", ")))
|
|
|
CROSSREFS
| Cf. A000533, A002275.
a(n) = A103091(n) - 1.
Sequence in context: A118612 A187628 A158866 * A109739 A163800 A180826
Adjacent sequences: A101075 A101076 A101077 * A101079 A101080 A101081
|
|
|
KEYWORD
| nonn,hard,more
|
|
|
AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Nov 30 2004
|
|
|
EXTENSIONS
| More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
|
| |
|
|
