a(n) is the average of the repeating terms of {T(n,k)} rounded to the nearest integer (rounding up if there's a choice), if {T(n,k)} is eventually periodic; = 0 otherwise. Here T(n,k) is the "phi/sigma tug-of-war sequence with seed n" defined by T(n,1) = phi(n), T(n,2) = sigma(phi(n)), T(n,3) = phi(sigma(phi(n))), ..., T(n,k) = phi(T(n,k-1)) if k is odd and = sigma(T(n,k-1)) if k is even.
A036840
a(n) is the average of the repeating terms of {T(n,k)} rounded to the nearest integer (rounding up if there's a choice), if {T(n,k)} is eventually periodic; = 0 otherwise. Here T(n,k) is the "phi/sigma tug-of-war sequence with seed n" defined by T(n,1) = phi(n), T(n,2) = sigma(phi(n)), T(n,3) = phi(sigma(phi(n))), ..., T(n,k) = phi(T(n,k-1)) if k is odd and = sigma(T(n,k-1)) if k is even.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =3a(4) =7a(5) =3a(6) =7a(7) =7a(8) =7a(9) =7a(10) =7a(11) =7a(12) =20a(13) =7a(14) =12a(15) =12a(16) =39a(17) =7a(18) =39a(19) =12a(20) =20a(21) =7a(22) =20a(23) =12a(24) =20a(25) =20a(26) =39a(27) =20a(28) =39a(29) =12
External references
- oeis: A036840