|
Search: id:A102017
|
|
|
| A102017 |
|
Indices of primes in sequence defined by A(0) = 19, A(n) = 10*A(n-1) - 41 for n > 0. |
|
+0
1
|
|
| 0, 1, 3, 10, 12, 25, 153, 195, 435, 528, 1110, 2562, 2640, 3232, 3882, 4255, 9297
(list; graph; listen)
|
|
|
OFFSET
|
1,3
|
|
|
COMMENT
|
Numbers n such that (130*10^n + 41)/9 is prime.
Numbers n such that digit 1 followed by n >= 0 occurrences of digit 4 followed by digit 9 is prime.
Numbers corresponding to terms <= 528 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
|
149 is prime, hence 1 is a term.
|
|
PROGRAM
|
(PARI) a=19; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-41)
(PARI) for(n=0, 1500, if(isprime((130*10^n+41)/9), print1(n, ", ")))
|
|
CROSSREFS
|
Cf. A000533, A002275.
a(n) = A102935(n) - 1.
Sequence in context: A088338 A020890 A031453 this_sequence A032916 A044994 A022415
Adjacent sequences: A102014 A102015 A102016 this_sequence A102018 A102019 A102020
|
|
KEYWORD
|
nonn,hard,more
|
|
AUTHOR
|
Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 28 2004
|
|
EXTENSIONS
|
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
|
|
|
Search completed in 0.002 seconds
|
