A094764 Trajectory of 7 under repeated application of the map n --> n + square excess of n.

7, 10, 11, 13, 17, 18, 20, 24, 32, 39, 42, 48, 60, 71, 78, 92, 103, 106, 112, 124, 127, 133, 145, 146, 148, 152, 160, 176, 183, 197, 198, 200, 204, 212, 228, 231, 237, 249, 273, 290, 291, 293, 297, 305, 321, 353, 382, 403, 406, 412, 424, 448, 455, 469, 497, 510, 536, 543

Offset: 0

Author

N. J. A. Sloane, Jun 10 2004

Keywords

• nonn

References

• H. Brocard, Note 2837, L'Intermédiaire des Mathématiciens, 11 (1904), p. 239.

Links

• S. H. Weintraub, An interesting recursion, Amer. Math. Monthly, 111 (No. 6, 2004), 528-530.

Crossrefs

Cf. A053186, A094761, A094763.

Programs

PARI

lista(nn) = {print1(n=7, ", "); for (k=2, nn, m = 2*n - sqrtint(n)^2; print1(m, ", "); n = m;);} \\ Michel Marcus, Oct 24 2015