a(n) = 2*n - phi(A003961(n)), where phi is Euler totient function and A003961 is fully multiplicative function with a(prime(i)) = prime(i+1).

A377985

a(n) = 2*n - phi(A003961(n)), where phi is Euler totient function and A003961 is fully multiplicative function with a(prime(i)) = prime(i+1).

Terms

    a(0) =1a(1) =2a(2) =2a(3) =2a(4) =4a(5) =4a(6) =4a(7) =-2a(8) =-2a(9) =8a(10) =10a(11) =0a(12) =10a(13) =8a(14) =6a(15) =-22a(16) =16a(17) =-4a(18) =16a(19) =4a(20) =2a(21) =20a(22) =18a(23) =-24a(24) =8a(25) =20a(26) =-46a(27) =-4a(28) =28a(29) =12

External references