A094763 Trajectory of 2 under repeated application of the map n -> n + square excess of n.

2, 3, 5, 6, 8, 12, 15, 21, 26, 27, 29, 33, 41, 46, 56, 63, 77, 90, 99, 117, 134, 147, 150, 156, 168, 192, 215, 234, 243, 261, 266, 276, 296, 303, 317, 345, 366, 371, 381, 401, 402, 404, 408, 416, 432, 464, 487, 490, 496, 508, 532, 535, 541, 553, 577, 578, 580, 584, 592, 608

Offset: 0

Author

N. J. A. Sloane, Jun 10 2004

Keywords

• nonn

Links

• Robert Israel, Table of n, a(n) for n = 0..10000
• S. H. Weintraub, An interesting recursion, Amer. Math. Monthly, 111 (No. 6, 2004), 528-530.

Crossrefs

Cf. A053186, A094761, A094764.

Programs

Maple

a[0]:= 2:
for n from 1 to 100 do a[n]:= f(a[n-1]) od:
seq(a[n],n=0..100); # Robert Israel, Jan 28 2018

PARI

lista(nn) = {print1(n=2, ", "); for (k=2, nn, m = 2*n - sqrtint(n)^2; print1(m, ", "); n = m;);} \\ Michel Marcus, Oct 23 2015