A080822 Primes in A058633.
23, 61, 67, 137, 149, 233, 547, 701, 709, 887, 1583, 1723, 1777, 2239, 2459, 2477, 2693, 3067, 3167, 3329, 3881, 3947, 3967, 4073, 5333, 5449, 5839, 6217, 6709, 6833, 8221, 8273, 8501, 8527, 8641, 9227, 9341, 10193, 10729, 10771, 11939, 12197, 12347
Offset: 1
Links
- Paolo Xausa, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
A006577[n_] := Length[NestWhileList[If[OddQ[#], 3*# + 1, #/2] &, n, # > 1 &]] - 1; Select[Accumulate[Array[A006577, 500]], PrimeQ] (* Paolo Xausa, Oct 01 2024 *)
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PARI
xpcount(n,p) = { ct=0; sr=0; for(x=1,n, p1 = x; while(p1>1, if(p1%2==0,p1/=2; ct++,p1 = p1*p+1; ct++) ); if(isprime(ct),print1(ct" "); sr+=1.0/ct) ); print(); print(sr) }
Extensions
Edited by Hauke Worpel and N. J. A. Sloane, Jun 03 2003