71221

Appears in sequences

• Numbers n such that there are exactly 4 primes p such that floor(n*log(n))+1<=p<=floor((n+1)*log(n+1))-1.at n=20A068362
• Number of binary strings of length n with no substrings equal to 0001 0101 or 0110.at n=19A164469
• Sequence defined by the recurrence formula a(n+1)=sum(a(p)*a(n-p)+k,p=0..n)+l for n>=1, with here a(0)=1, a(1)=7, k=1 and l=-1.at n=7A177177
• Fibonacci sequence beginning 13, 9.at n=19A206609