68101

Appears in sequences

• Strong pseudoprimes to base 37.at n=21A020263
• Strong pseudoprimes to base 42.at n=22A020268
• Strong pseudoprimes to base 78.at n=23A020304
• a(n) = T(2n,n-1), T given by A026747.at n=7A026749
• Composite numbers k such that k divides F(k-1) where F(j) are the Fibonacci numbers.at n=20A069106
• Sarrus numbers n (A001567) which satisfy mu(n) = -1 and which are not Super-Poulet numbers (A050217).at n=27A074380
• Sarrus numbers with more than 2 distinct prime factors.at n=35A080747
• Pseudoprimes to bases 2 and 5.at n=14A083732
• Numbers k that divide Fibonacci(k-1) but do not divide Fibonacci(k) - 1.at n=10A094410
• Pseudotwinprimes p+2 for primes p such that p+2 divides p^(p+2)+2 and p+2 is composite.at n=24A100873
• Smallest number that is a sum of two n-th powers of positive rationals but not of two n-th powers of positive integers.at n=2A111152
• 3-almost prime octagonal numbers.at n=33A129927
• Increasing gaps between 2-pseudoprimes (lower end).at n=11A175736
• Numbers m such that exactly half of the a such that 0<a<m and (a,m)=1 satisfy a^(m-1) == 1 (mod m).at n=16A191311
• Numbers in A191311 but not in A129521.at n=6A191592
• Odd non-Carmichael numbers with increasing numbers of bases to which they are pseudoprimes.at n=22A194946
• Fermat pseudoprimes to base 2 of the form (6*k - 1)*((6*k - 2)*n + 1), where k and n are positive integers.at n=33A210993
• Composite numbers k such that k divides Fibonacci(k+1) or Fibonacci(k-1) and 2^(k-1) == 1 (mod k).at n=3A214434
• Fermat pseudoprimes to base 2 of the form (6*k + 1)*(6*k*n + 1), where k, n are integers different from 0.at n=33A214607
• Fermat pseudoprimes to base 2 of the form m*n^2 + (11*m - 23)*n + 19*m - 49, where m, n >= 0.at n=27A215326