26609

Appears in sequences

• a(n) = Fibonacci(n+1) - 2^floor(n/2).at n=22A005672
• Numbers k such that sigma(k+2) = sigma(k).at n=31A007373
• a(n) = Fibonacci(n) - 2^(floor(n/2)).at n=23A028892
• a(n) = Sum_{k=1..n} T(n,k), array T as in A049790.at n=42A049791
• Numbers k such that A065608(k) = A065608(k+2).at n=16A065064
• Expansion of x/((1-x-x^3)*(1-x)^7).at n=11A144901
• a(n) = Fibonacci(n-2) + 2*a(n-2) - (n mod 2).at n=22A192727
• Numbers k such that k and k+2 have the same number (A000005) and sum of divisors (A000203).at n=13A229254
• Let b(k) = A164555(k)/A027642(k), the sequence of "original" Bernoulli numbers with -1 instead of A164555(0)=1; then a(n) = numerator of the n-th term of the binomial transform of the b(k) sequence.at n=12A235774
• Number of balanced parenthesis expressions of length 2n and depth 3.at n=9A258109
• Number of Dyck paths of semilength 4*n and height n.at n=3A289474
• Number A(n,k) of Dyck paths of semilength k*n and height n; square array A(n,k), n>=0, k>=0, read by antidiagonals.at n=31A289481
• a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 0, a(1) = 0, a(2) = 1, a(3) = 2.at n=20A295724
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n-1), where a(0) = 2, a(1) = 3, b(0) = 1, b(1) = 4, and (a(n)) and (b(n)) are increasing complementary sequences.at n=15A296291
• Products of three distinct strong primes.at n=23A363782
• a(n) is the number of subsets of the first n primes whose sum is not a prime.at n=15A364535
• Numbers k such that k^6*2^k - 1 is a prime.at n=14A367478
• Numbers k such that the sum of the numbers from 1 to k and that from 1 to k+1 share the same sum of divisors.at n=19A375819
• Numbers k such that s(k) = s(k+2), where s(k) is the sum of odd divisors of k (A000593).at n=11A387920