27870

Appears in sequences

• Number of points in N^n of norm <= 2.at n=29A055417
• Composite n such that (n-1)*phi(n) is a perfect square.at n=25A069953
• Diagonal in array of n-gonal numbers A081422.at n=29A081437
• Number of pairs with two different elements which can be obtained by selecting unique elements from two sets with n+1 and n^2 elements respectively and n common elements.at n=30A085490
• a(0)=1; a(n) = lcm((number of earlier terms which are coprime to n), (sum of the earlier terms which are coprime to n)).at n=11A128268
• a(n) = 961*n + 1.at n=28A158414
• Numbers that are 4-digit palindromes in at least 2 bases.at n=34A180453
• Smallest palindromic numbers of length 4 in two bases differing by n.at n=13A216843
• Numbers k such that Bernoulli number B_{k} has denominator 14322.at n=36A295588
• Number of integer partitions of n whose negated run-lengths are not unimodal.at n=42A332639