|
%I #10 Jun 24 2022 20:10:07
%S 2,6,14,46,110,366,878,2926,19310,52078,314222,1362798,3459950,
%T 11848558,78957422,615828334,1689570158,10279504750,44639243118,
%U 113358719854,663114533742,2862137789294,20454323833710,301929300544366,1427829207386990,3679629021072238
%N Numbers formed by setting bits representing odd primes, where bit_no = (prime - 1)/2. Setting bit number b is the same as OR-ing with 2^b (i.e., bit numbers start at zero).
%F a(n) = setbit(a(n-1),(p-1)/2) where p is the n-th odd prime.
%e a(3) = 14 because 3, 5 and 7 are odd primes so therefore bits 1, 2 and 3 are set and bit zero is not. 1110_2 = 14.
%o #!/usr/bin/python import gmpy a = gmpy.mpz(0) i = 0 for p in range(3,100,2): if gmpy.is_prime(p): a = gmpy.setbit(a,(p-1)/2) i += 1 print i,a
%Y Partial sums of A061285.
%K nonn
%O 1,1
%A _Alan Griffiths_, Oct 08 2007
|
