25863

Appears in sequences

• a(n) = floor(n(n-1)(n-2)(n-3)/19).at n=28A011929
• Positive numbers k such that k and 2*k are anagrams in base 9 (written in base 9).at n=37A023079
• Numbers n such that 219*2^n-1 is prime.at n=12A050861
• Rounded volume of a regular dodecahedron with edge length n.at n=15A071401
• Numbers n with property that average digit of n^2 is s=7.at n=34A164773
• Number of distinct values of the sum of 5 products of three 0..n integers.at n=17A225262
• Number of rooted unlabeled 4-cactus graphs on 3n+1 nodes.at n=8A287891
• Array read by antidiagonals: T(n,k) is the number of rooted unlabeled k-gonal cacti having n polygons.at n=74A332648
• a(n) = Sum_{k=1..n} sigma(k)*sigma(2*k), where sigma(n) = A000203(n) is the sum of the divisors of n.at n=21A347108