A192505 Non-ludic numbers that are prime numbers.

19, 31, 59, 73, 79, 101, 103, 109, 113, 137, 139, 151, 163, 167, 191, 197, 199, 229, 241, 251, 263, 269, 271, 281, 293, 311, 317, 347, 349, 367, 373, 379, 401, 409, 439, 443, 449, 457, 461, 479, 487, 491, 499, 521, 523, 547, 557, 563, 569, 571, 587, 599, 601

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

Formula

(1-A010051(a(n)))*A192490(a(n)) = 1.

Mathematica

a3309[nmax_] := a3309[nmax] = Module[{t = Range[2, nmax], k, r = {1}}, While[Length[t] > 0, k = First[t]; AppendTo[r, k]; t = Drop[t, {1, -1, k}]]; r];
ludicQ[n_, nmax_] /; 1 <= n <= nmax := MemberQ[a3309[nmax], n];
terms = 1000;
f[nmax_] := f[nmax] = Select[Range[nmax], !ludicQ[#, nmax] && PrimeQ[#]&] // PadRight[#, terms]&;
f[nmax = terms];
f[nmax = 2 nmax];
While[f[nmax] != f[nmax/2], nmax = 2 nmax];
seq = f[nmax] (* Jean-François Alcover, Dec 10 2021, after Ray Chandler in A003309 *)

Prog

(Haskell)
a192505 n = a192505_list !! (n-1)
a192505_list = filter ((== 1) . a010051) a192607_list

Crossrefs

Intersection of A000040 and A192607.

Cf. A010051, A192490.

Sequence in context: A276569 A276447 A214796 * A141184 A033212 A104227

Adjacent sequences: A192502 A192503 A192504 * A192506 A192507 A192508

Keyword

nonn

Author

Reinhard Zumkeller, Jul 05 2011

Status

approved