OFFSET
1,1
COMMENTS
Read each binary representation of the primes from right to left and then AND respective digits to form the binary equivalent of each term of this sequence.
Indices of 1's: 2, 6, 18, 54, 564, 3512, 6542, 564163, 2063689, 54400028, ... - Alex Ratushnyak, Apr 22 2012
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Wikipedia, Bitwise operation
EXAMPLE
For n = 15, a(15) = 37 because the 15th prime is 47 and the 16th is 53, which have binary representations of 101111 and 110101 respectively; the bitwise AND of these values is 100101 which is the binary representation of 37:
101111
& 110101
--------
100101
MAPLE
read("transforms") ; A175330 := proc(n) ANDnos(ithprime(n), ithprime(n+1)) ; end proc: seq(A175330(n), n=1..60) ; # R. J. Mathar, Apr 15 2010
# second Maple program:
a:= n-> Bits[And](ithprime(n), ithprime(n+1)):
seq(a(n), n=1..70); # Alois P. Heinz, Apr 15 2020
MATHEMATICA
a[n_] := Prime[n]~BitAnd~Prime[n+1];
Array[a, 60] (* Jean-François Alcover, Jan 11 2021 *)
PROG
(PARI) a(n) = bitand(prime(n), prime(n+1)); \\ Michel Marcus, Apr 16 2020
(Scala) val prime: LazyList[Int] = 2 #:: LazyList.from(3).filter(i => prime.takeWhile {
j => j * j <= i
}.forall {
k => i % k != 0
})
(0 to 63).map(n => prime(n) & prime(n + 1)) // Alonso del Arte, Apr 18 2020
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Leroy Quet, Apr 07 2010
EXTENSIONS
More terms from R. J. Mathar, Apr 15 2010
STATUS
approved