A103387 Primes in A103377.

2, 3, 5, 7, 17, 31, 71, 127, 157, 227, 257, 293, 349, 419, 503, 16007, 32783, 33329, 80429, 220919, 786433, 878831, 85790399, 10666238497, 394760836573, 22265159019759079, 617347651958903360669, 98459899570803393815965301

Offset: 1

Author

Jonathan Vos Post, Feb 15 2005

Keywords

• easy
• nonn

Crossrefs

Cf. A103377, A103397.

Programs

Mathematica

SemiprimeQ[n_]:=Plus@@FactorInteger[n][[All, 2]]?2; Clear[a]; k=9; Do[a[n]=1, {n, k+1}]; a[n_]:=a[n]=a[n-k]+a[n-k-1]; A103377=Array[a, 100] A103387=Union[Select[Array[a, 1000], PrimeQ]] A103397=Union[Select[Array[a, 300], SemiprimeQ]] N[Solve[x^10 - x - 1 == 0, x], 111][[2]]

Formula

Intersection of A103377 with A000040.