45812984491
domain: N
Appears in sequences
- a(n) = (2^(2*n + 1) + 1)/3.at n=18A007583
- A Jacobsthal sequence trisection.at n=12A082311
- Generalized multiplicative Jacobsthal sequence.at n=37A087463
- Sylvester-Jacobsthal cyclotomic numbers.at n=36A105603
- a(n) = (2^prime(n) + 1)/3.at n=10A126614
- Composite numbers of the form (2^p+1)/3 where p is a prime.at n=1A127955
- Nonprime numbers of the form 1 + Sum_{k=1..m} 2^(2*k - 1).at n=8A127959
- First quadrisection of A139763 (1, 2, 3, 4, 11, ...).at n=9A139792
- a(n) = -1/6 + (-1)^n/2 + 2*4^n/3.at n=18A140322
- Numbers of the form (2^(p*q)-1) /((2^p-1)*(2^q-1)), where p>q are primes.at n=17A140803
- The Jacobsthal sequence, dropping each third term.at n=24A141355
- Interleave A007583 and A000012.at n=36A166752
- Jacobsthal numbers which are semiprimes.at n=7A277356
- Numbers k such that both k and 2k-1 are Poulet numbers (Fermat pseudoprimes to base 2).at n=10A298758
- a(n) = Sum_{k=0..n} binomial(2*n+1,3*k).at n=18A387868