196607

Appears in sequences

• a(0) = 1; a(n) = 3*2^n - 1, for n > 0.at n=16A052940
• a(2n) = 2*2^n - 1, a(2n+1) = 3*2^n - 1.at n=33A052955
• a(0) = 0; for n > 0, a(n) = 3*2^(n-1) - 1.at n=17A055010
• Variation on Ulam numbers: a(1) = 1; a(2) = 2; for n>2, a(n) = smallest (n odd) or largest (n even) number > a(n-1) that is a unique sum of two distinct earlier terms.at n=33A081026
• a(0) = 1; for n > 0, a(n) = 3*2^(n-1) - 1.at n=17A083329
• Add 1, double, add 1, double, etc.at n=33A083416
• Smallest composite number with exactly n 1's in binary representation.at n=16A089226
• a(n) = 3*2^floor((n-1)/2) + (-1)^n.at n=32A097581
• Numbers of the form 3*2^(p - 1) - 1 where p is prime.at n=6A097743
• Expansion of g.f.: (3+x+2*x^2-2*x^3)/((1-2*x)*(1+x^2)).at n=16A100720
• Smallest semiprime with Hamming weight n (i.e., smallest semiprime with exactly n ones when written in binary), or -1 if no such number exists.at n=16A102029
• Slater-Velez permutation sequence of the 2nd kind.at n=32A129198
• Smallest nonprime with Hamming weight n (i.e., with exactly n 1's when written in binary).at n=16A140330
• a(n) = 3*2^n - 1.at n=16A153893
• Numbers of the form i*8^j-1 (i=1..7, j >= 0).at n=40A165804
• Numbers of the form i*4^j-1 (i=1..3, j >= 0).at n=26A180516
• a(n) = 3*4^n-1.at n=8A198693
• a(n) = 6*8^n-1.at n=5A198854
• a(n) = a(n-1) + 2*a(n-2) with n>1, a(0)=2, a(1)=7.at n=16A201630
• Numbers in A206853 without proper divisors > 1 from the same sequence.at n=42A209630