|
| |
|
|
A101533
|
|
Indices of primes in sequence defined by A(0) = 67, A(n) = 10*A(n-1) - 13 for n > 0.
|
|
0
| | |
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Numbers n such that (590*10^n + 13)/9 is prime.
Numbers n such that digit 6 followed by n >= 0 occurrences of digit 5 followed by digit 7 is prime.
Numbers corresponding to terms <= 695 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
| 65557 is prime, hence 3 is a term.
|
|
|
PROG
| (PARI) a=67; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-13)
(PARI) for(n=0, 1500, if(isprime((590*10^n+13)/9), print1(n, ", ")))
|
|
|
CROSSREFS
| Cf. A000533, A002275.
a(n) = A103040(n) - 1.
Sequence in context: A026624 A026690 A036676 * A138803 A048492 A006776
Adjacent sequences: A101530 A101531 A101532 * A101534 A101535 A101536
|
|
|
KEYWORD
| nonn,hard,more
|
|
|
AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 06 2004
|
|
|
EXTENSIONS
| More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
|
| |
|
|
