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A133155 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).

%I A133155 #13 Dec 03 2024 19:53:38
%S A133155 2,6,14,46,110,366,878,2926,19310,52078,314222,1362798,3459950,
%T A133155 11848558,78957422,615828334,1689570158,10279504750,44639243118,
%U A133155 113358719854,663114533742,2862137789294,20454323833710,301929300544366,1427829207386990,3679629021072238
%N A133155 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 A133155 a(n) = setbit(a(n-1),(p-1)/2) where p is the n-th odd prime.
%e A133155 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 A133155 (Python)
%o A133155 import gmpy
%o A133155 a = gmpy.mpz(0)
%o A133155 i = 0
%o A133155 for p in range(3,100,2):
%o A133155     if gmpy.is_prime(p):
%o A133155         a = gmpy.setbit(a,(p-1)/2)
%o A133155         i += 1
%o A133155         print(i,a)
%Y A133155 Partial sums of A061285.
%K A133155 nonn
%O A133155 1,1
%A A133155 _Alan Griffiths_, Oct 08 2007