49005

Appears in sequences

• Odd numbers k that divide phi(k)*sigma(k).at n=27A015706
• Numbers n such that n*phi(n-1) is a perfect square.at n=26A069069
• a(n) = n*(4n^2 - 1)^2.at n=5A069073
• Numbers k for which the quotient q(k)=(k+rev(k))/abs(k-rev(k)) is an integer.at n=21A087993
• Numbers k such that k*sigma(k)*sigma(sigma(k)) is a square.at n=7A116004
• Numbers n such that n^8+8 and n^8-8 are prime.at n=34A239503
• Odd numbers of the form (m*k)^2/(m^2-k^2) for distinct integers m and k.at n=28A259288
• Number of septenary sequences of length n such that no two consecutive terms have distance 3.at n=6A287810
• Intersection of A228058 and A260021.at n=1A354362
• Numbers k such that R(k)/k is of the form (m + 1)/m, where R(k) is the digital reversal of k.at n=10A376259
• a(n) is the conjectured largest number such that both a(n) and a(n) - n are 11-smooth numbers, or 0 if no such number exists. a(n) can be less than n.at n=4A392256