|
| |
|
|
A101713
|
|
Indices of primes in sequence defined by A(0) = 43, A(n) = 10*A(n-1) - 27 for n > 0.
|
|
0
| |
|
|
0, 2, 6, 9, 39, 418, 448, 1736, 2244, 3130, 3812, 5344, 5658, 5680, 8409, 9096
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Numbers n such that 40*10^n + 3 is prime.
Numbers n such that digit 4 followed by n >= 0 occurrences of digit 0 followed by digit 3 is prime.
Numbers corresponding to terms <= 448 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
| 4003 is prime, hence 2 is a term.
|
|
|
PROG
| (PARI) a=43; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-27)
(PARI) for(n=0, 1500, if(isprime(40*10^n+3), print1(n, ", ")))
|
|
|
CROSSREFS
| Cf. A000533, A002275.
a(n) = A101397(n) - 1.
Sequence in context: A093397 A082459 A129831 * A117541 A095105 A052194
Adjacent sequences: A101710 A101711 A101712 * A101714 A101715 A101716
|
|
|
KEYWORD
| nonn,hard,more
|
|
|
AUTHOR
| Klaus Brockhaus (klaus-brockhaus(AT)t-online.de) and Walter Oberschelp (oberschelp(AT)informatik.rwth-aachen.de), Dec 14 2004
|
|
|
EXTENSIONS
| More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008
|
| |
|
|
