A371555 Smallest position m such that A005350(m)=n.

1, 4, 6, 9, 10, 14, 15, 17, 22, 23, 24, 26, 29, 35, 36, 37, 39, 40, 42, 45, 49, 56, 57, 58, 59, 61, 62, 64, 67, 68, 70, 73, 77, 82, 90, 91, 92, 93, 95, 96, 97, 99, 100, 102, 105, 106, 108, 111, 115, 116, 118, 121, 125, 130, 136, 145, 146, 147, 148, 149, 151, 152, 153, 155

Offset: 1

Author

R. J. Mathar, Mar 27 2024

Keywords

• nonn

Comments

Greedy inverse of A005350.

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000
• Michael De Vlieger, Log log scatterplot of a(n), n = 1..2^20.

Crossrefs

Cf. A005350, A188163.

Programs

Maple

A371555 := proc(n)
    local a;
    for a from 1 do
        if A005350(a) = n then
            return a;
        end if;
    end do:
end proc:
seq(A371555(n),n=1..100);

Mathematica

r = 0; a[1] = a[2] = a[3] = 1; a[n_] := a[n] = a[a[n - 1]] + a[n - a[n - 1]]; Reap[Do[If[a[n] > r, Sow[n]; r = a[n]], {n, 155}]][[-1, 1]] (* Michael De Vlieger, Mar 27 2024, after Jean-François Alcover at A005350 *)