21586

Appears in sequences

• a(n) = Sum_{j=1..n} j*prime(j).at n=25A014285
• a(n) = Sum_{k=1..n} k*[ (n/k)*[ (n/k)*[ n/k ] ] ].at n=23A024933
• Number of dissimilar ternary squarefree words of length n+1.at n=33A060688
• a(0)=1. a(n) = sum of the earlier terms which are divisible by (the number of 1's in the binary representation of n).at n=20A123757
• Denominators of r-Egyptian fraction expansion for sqrt(2) - 1, where r(k) = 1/k!.at n=4A270519
• Somos's sequence {a(4,n)} defined in comment in A018896.at n=25A271341