A396619 a(n) = r(n,n), where r(1,k)=f(k)=floor(k*c), r(n,k)=f(r(n-1,k)), c=Pi.

3, 18, 87, 364, 1448, 5416, 19836, 74870, 262213, 917960, 3158943, 10842201, 36690183, 124716138, 425993118, 1430648672, 4749540248, 15725455165, 52295020828, 172195798783, 568455044734, 1891544349000, 6216264579905, 20327990695444, 66528129183957

Offset

1,1

Comments

a(n + 1)/a(n) approaches c erratically.

Links

Table of n, a(n) for n=1..25.

Mathematica

c = Pi; f[k_] := f[k] = Floor[c*k];
r[1, k_] := f[k]; r[n_, k_] := r[n, k] = f[r[n - 1, k]];
Table[r[n, n], {n, 1, 100}]

Crossrefs

Cf. A396385, A396620, A396621.

Sequence in context: A301996 A218924 A390501 * A037295 A290331 A124811

Adjacent sequences: A396616 A396617 A396618 * A396620 A396621 A396622

Keyword

nonn

Author

Clark Kimberling, Jun 03 2026

Status

approved