OFFSET
1,2
COMMENTS
a(2) and a(121) are primes. Are there any more?
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..168
EXAMPLE
a(4) = 110101 because the string '00110101' has 1's at the prime indices 2,3,5,7 and the first two zeros are dropped.
MATHEMATICA
a[n_] := FromDigits[Boole @ PrimeQ[Range[Prime[n]]]]; Array[a, 12] (* Amiram Eldar, Aug 18 2020 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Jason Earls, Jun 23 2005
STATUS
approved