|
Search: id:A101059
|
|
|
| A101059 |
|
Indices of primes in sequence defined by A(0) = 87, A(n) = 10*A(n-1) - 53 for n > 0. |
|
+0
1
|
| |
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Numbers n such that (730*10^n + 53)/9 is prime.
Numbers n such that digit 8 followed by n >= 0 occurrences of digit 1 followed by digit 7 is prime.
Numbers corresponding to terms <= 674 are certified primes.
|
|
REFERENCES
|
Klaus Brockhaus and Walter Oberschelp, Zahlenfolgen mit homogenem Ziffernkern, MNU 59/8 (2006), pp. 462-467.
|
|
FORMULA
|
a(n) = A103072(n) - 1. - Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 01 2008
|
|
EXAMPLE
|
8117 is prime, hence 2 is a term.
|
|
PROGRAM
|
(PARI) a=87; for(n=0, 1500, if(isprime(a), print1(n, ", ")); a=10*a-53)
(PARI) for(n=0, 1500, if(isprime((730*10^n+53)/9), print1(n, ", ")))
|
|
CROSSREFS
|
Cf. A000533, A002275.
Sequence in context: A099888 A046161 A092978 this_sequence A101658 A006573 A009662
Adjacent sequences: A101056 A101057 A101058 this_sequence A101060 A101061 A101062
|
|
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
|
|
|
Search completed in 0.002 seconds
|
