45877

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 47.at n=0A031635
• Numbers k such that the product of Euler phi of the 2 consecutive integers {k,k+1} is a 4th power: if sqrt(sqrt(phi(k)*phi(k+1))) is an integer, then k is here.at n=15A082788
• Let L_1 = (1) and L_2 = (1, 2); for any n > 2, L_n is obtained by inserting one n between each pair of consecutive terms of L_{n-1} coprime to n; a(n) gives the number of n's in L_n.at n=29A370857