88561
domain: N
Appears in sequences
- Strong pseudoprimes to base 62.at n=35A020288
- Strong pseudoprimes to base 96.at n=31A020322
- Numbers k that divide the (left) concatenation of all numbers <= k written in base 5 (most significant digit on left).at n=12A029474
- Pseudoprimes to both base 2 and base 3, i.e., intersection of A001567 and A005935.at n=20A052155
- Sarrus numbers n (A001567) which satisfy mu(n) = -1 and which are not Super-Poulet numbers (A050217).at n=31A074380
- For p = prime(n), a(n) is the smallest base-2 pseudoprime N (that is, 2^(N-1) = 1 mod N) such that p divides N.at n=21A085999
- Composite numbers k such that 2^k-2 and 3^k-3 are both divisible by k and k is not a Carmichael number (A002997).at n=6A153513
- a(n) = (3 + 2*n + 6*n^2 + 4*n^3)/3.at n=40A166464
- Composite numbers n with the property that phi(n) divides (n-1)^2.at n=18A173703
- 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=18A191311
- Numbers in A191311 but not in A129521.at n=7A191592
- Odd non-Carmichael numbers with increasing numbers of bases to which they are pseudoprimes.at n=24A194946
- Fermat pseudoprimes to base 2 with three prime factors.at n=31A215672
- Composite integers k such that 2^k == 2 (mod k*(k+1)).at n=19A217465
- Fermat pseudoprimes to base 2 which are not Euler pseudoprimes to base 2.at n=31A227136
- The phi-radical numbers: composite numbers m such that rad(phi(m)) = rad(m-1).at n=10A306478
- "Strong impostors" not divisible by 4: Those numbers s !== 0 (mod 4) such that lambda(s) | 2(s-1), where lambda is the Carmichael function (A002322).at n=47A318555
- Number of nonnegative integer matrices with sum of entries equal to n and no zero rows or columns, whose entries are all distinct.at n=26A321660
- Composite numbers k of the form 4u+1 for which the odd part of phi(k) divides k-1.at n=34A339870
- Intersection of A137409 and A339870: Composite numbers k of the form 4u+1 having more than one prime factor of type 4u+3, and for which the odd part of phi(k) divides k-1.at n=8A339875