1,3

a(n) = A007966(A007969(n)) = A007969(n) / A191855(n);

(a(n), A191855(n)) is a 1-happy couple;

notation: B in the Conway link.

Table of n, a(n) for n=1..80.

J. H. Conway, On Happy Factorizations, J. Integer Sequences, Vol. 1, 1998, #1.

a(n) * A191860(n)^2 + 1 = A191854(n) * A191861(n)^2.

Sequence in context: A034869 A205858 A053222 * A129646 A165401 A213074

Adjacent sequences: A191851 A191852 A191853 * A191855 A191856 A191857

nonn

Reinhard Zumkeller, Jun 18 2011

approved