20237
domain: N
Appears in sequences
- Number of divisor chains of length n: permutations s_1,s_2,...,s_n of 1,2,...,n such that for all j=1,2,...,n, s_j divides Sum_{i=1..j} s_i.at n=24A067957
- Smallest k such that n, k and n+k have the same prime signature (canonical form), or 0 if no such number exists.at n=39A085080
- Numbers k such that 3^k - 14 is prime.at n=16A219038
- Positions of 3's in A234323.at n=54A234804
- Rectangular array A read by upward antidiagonals: A(n,m) is the number of total difunctional (regular) binary relations between an n-element set and an m-element set.at n=39A265706
- Rectangular array A read by upward antidiagonals: A(n,m) is the number of surjective difunctional (regular) binary relations between an n-element set and an m-element set.at n=41A265707
- Prime time numbers on 6-digit clocks: numbers of the form HMMSS where H, MM, SS are primes, H < 24, MM and SS < 60.at n=11A295014
- Worst-case of deterministic state complexity for cyclic shift of binary language with state complexity n.at n=3A306990