A070872 Numbers k such that A070871(k) = k.

1, 2, 6, 66, 216, 1159, 2184

Offset: 1

Author

J. H. Conway, May 17 2002

Keywords

• nonn

Comments

Could be called nutritionally balanced numbers.

Crossrefs

Cf. A002487, A070871.

Programs

Mathematica

a[0] = 1; a[n_] := a[n] = If[ OddQ[n], a[n/2 - 1/2], a[n/2] + a[n/2 - 1]]; Do[ If[ a[n]*a[n - 1] == n, Print[n]], {n, 1, 5*10^6}]

Extensions

More terms from David W. Wilson, May 17 2002