login
A247974
Numbers k such that A247973(k+1) = A247973(k).
4
1, 6, 11, 15, 20, 25, 29, 34, 39, 43, 48, 52, 57, 62, 66, 71, 76, 80, 85, 90, 94, 99, 104, 108, 113, 118, 122, 127, 132, 136, 141, 146, 150, 155, 160, 164, 169, 174, 178, 183, 188, 192, 197, 202, 206, 211, 216, 220, 225, 230, 234, 239, 244, 248, 253, 258
OFFSET
1,2
MATHEMATICA
$RecursionLimit = Infinity; z = 400; v[1] = 0; v[2] = 1;
v[n_] := v[n] = v[n - 1]/(n - 2) + v[n - 2];
TableForm[Table[{n, N[Pi - (4 n + 2)/(v[2 (n + 1)]^2)], N[1/n]}, {n, 1, 10}]]
g[n_] := g[n] = Select[Range[z], Pi - (4 # + 2)/(v[2 (# + 1)]^2) < 1/n &, 1];
u = Flatten[Table[g[n], {n, 1, z}]] (* A247973 *)
d = Differences[u]
Flatten[Position[d, 0]] (* A247974 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Sep 28 2014
STATUS
approved