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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 (list; graph; refs; listen; history; text; internal format)
 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. LINKS Table of n, a(n) for n=1..20. 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 Adjacent sequences: A101301 A101302 A101303 * A101305 A101306 A101307 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

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Last modified April 17 15:20 EDT 2024. Contains 371764 sequences. (Running on oeis4.)