login
a(n) = bitwise OR of prime(n) and prime(n+1).
4

%I #31 Oct 13 2024 00:17:51

%S 3,7,7,15,15,29,19,23,31,31,63,45,43,47,63,63,63,127,71,79,79,95,91,

%T 121,101,103,111,111,125,127,255,139,139,159,151,159,191,167,175,191,

%U 183,191,255,197,199,215,223,255,231,237,239,255,251,507,263,271,271,287

%N a(n) = bitwise OR of prime(n) and prime(n+1).

%C Read each binary representation of the primes from right to left and then OR respective digits to form the binary equivalent of each term of this sequence.

%H Rémy Sigrist, <a href="/A175329/b175329.txt">Table of n, a(n) for n = 1..10000</a>

%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Bitwise operation">Bitwise operation</a>

%p read("transforms") ; A175329 := proc(n) ORnos(ithprime(n),ithprime(n+1)) ; end proc: seq(A175329(n),n=1..60) ; # _R. J. Mathar_, Apr 15 2010

%p # second Maple program:

%p a:= n-> Bits[Or](ithprime(n), ithprime(n+1)):

%p seq(a(n), n=1..70); # _Alois P. Heinz_, Apr 16 2020

%t A175329[n_]:=BitOr[Prime[n],Prime[n+1]];Array[A175329,100] (* _Paolo Xausa_, Oct 13 2023 *)

%t BitOr@@#&/@Partition[Prime[Range[60]],2,1] (* _Harvey P. Dale_, Mar 01 2024 *)

%o (PARI) a(n) = bitor(prime(n), prime(n+1)); \\ _Michel Marcus_, Apr 20 2020

%Y Cf. A000040, A175330 (bitwise AND).

%Y Cf. A086799 (bitwise OR of n and n-1).

%K base,nonn,easy

%O 1,1

%A _Leroy Quet_, Apr 07 2010

%E More terms from _R. J. Mathar_, Apr 15 2010