OFFSET
1,1
COMMENTS
Numbers whose binary representation is 1 repeated (prime(n)+1) times.
The only prime term is 7.
FORMULA
a(n) = A101304(n) - 2.
EXAMPLE
For n=3; a(3) = 2^(prime(3) + 1) - 1 = 2^(5 + 1) - 1 = 2^6 - 1 = 63.
MAPLE
MATHEMATICA
f[n_] := 2^(Prime[n]+1)-2; Array[f, 20] (* Robert G. Wilson v, Dec 21 2016 *)
2^(Prime[Range[20]]+1)-1 (* Harvey P. Dale, Jul 29 2024 *)
PROG
(Magma) [2^(NthPrime(n)+1)-1: n in[1..50]]
(PARI) a(n) = 2^(prime(n)+1)-1 \\ Felix Fröhlich, Dec 21 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaroslav Krizek, Dec 21 2016
STATUS
approved