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A101304
a(n) = 2^(prime(n) + 1) + 1.
1
9, 17, 65, 257, 4097, 16385, 262145, 1048577, 16777217, 1073741825, 4294967297, 274877906945, 4398046511105, 17592186044417, 281474976710657, 18014398509481985, 1152921504606846977, 4611686018427387905, 295147905179352825857, 4722366482869645213697
OFFSET
1,1
COMMENTS
Decimal numbers in which binary form is given by 1x1 where x is the digit 0 repeated a prime number of times.
EXAMPLE
prime(n)=a ==> convert(1 (0xa times) 1,decimal,2) = b # note a zeros
::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
prime(1)=2 ==> convert(1001,decimal,2) = 9 # note 2 zeros
prime(2)=3 ==> convert(10001,decimal,2) = 17 # note 3 zeros
prime(3)=5 ==> convert(1000001,decimal,2) = 65 # note 5 zeros
prime(3)=7 ==> convert(100000001,decimal,2) = 257 # note 7 zeros
MAPLE
convert(1001, decimal, 2), convert(10001, decimal, 2), convert(1000001, decimal, 2), convert(100000001, decimal, 2), convert(1000000000001, decimal, 2), convert(100000000000001, decimal, 2), convert(1000000000000000001, decimal, 2), convert(100000000000000000001, decimal, 2), convert(1000000000000000000000001, decimal, 2), convert(1000000000000000000000000000001, decimal, 2), convert(100000000000000000000000000000001, decimal, 2);
MATHEMATICA
Table[2^(Prime[n] + 1) + 1, {n, 18}] (* Robert G. Wilson v, Dec 22 2004 *)
PROG
(Magma) [2^(NthPrime(n)+1)+1: n in [1..20]]; // Vincenzo Librandi, Jul 30 2015
CROSSREFS
Cf. A000051.
Sequence in context: A147138 A282764 A319018 * A146601 A121955 A151793
KEYWORD
nonn
AUTHOR
Jorge Coveiro, Dec 22 2004
EXTENSIONS
Edited and extended by Robert G. Wilson v, Dec 22 2004
a(19)-a(20) from Vincenzo Librandi, Jul 30 2015
STATUS
approved