26222

Appears in sequences

• Numbers k such that 60*R_k + 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=25A056658
• Structured pentagonal icositetrahedral numbers (vertex structure 10).at n=13A100168
• Number of Ruth-Aaron numbers (with multiplicity) less than 10^n.at n=9A101805
• Triangle H(n,j) (n=1,2,3,..., j=2,3,4,...) read by rows: let X(k,l,n) := Stirling2(n,k)*Stirling2(k,l) for 1<=k<=n and 1<=l<=k. Then H(n,j)= sum_{k+l=j, 1<=k<=n and 1<=l<=k} X(k,l,n).at n=54A136206
• Numbers n with digits 2 and 6 only.at n=38A284632
• The number of coreful abundant numbers (A308053) below 10^n.at n=5A308054
• a(n) = 1 + Sum_{k=1..n-3} a(k) * a(n-k-3).at n=23A346075