1,2
Cf. A054431
Table of n, a(n) for n=1..75.
a(n) = A054424_as_array(n)
position_in_whole_SB_tree_or_zero := (n, m) -> `if`((1 = gcd(n, m)), (frac2position_in_whole_SB_tree(n/m)), (0));
A054424_as_array := n -> position_in_whole_SB_tree_or_zero( ((n-((trinv(n)*(trinv(n)-1))/2))+1), ((((trinv(n)-1)*(((1/2)*trinv(n))+1))-n)+1) );
trinv := n -> floor((1+sqrt(1+8*n))/2); # Gives integral inverses to the triangular numbers
Sequence in context: A004180 A011418 A214158 * A217101 A265516 A256295
Adjacent sequences: A054422 A054423 A054424 * A054426 A054427 A054428
nonn,tabl,nice
Antti Karttunen
approved