A102200 Iccanobirt semiprimes (10 of 15): Semiprime numbers in A102120.

4, 53122, 412441, 2360934421, 2982905123, 1968515515, 8282454457, 17281502461, 88998294238681, 858342429826762, 2350396241873433799, 25572406084465911331237801, 52170015710352407496920694341, 798986767053692909522422712521, 718154384550161644441959876349

Offset: 1

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

• nonn
• less
• base

Crossrefs

Cf. A001358, A102120, A102180, A102191-A102205.

Programs

Mathematica

nxt[{a_,b_,c_}]:={b,c,IntegerReverse[c+IntegerReverse[b]+a]};Select[NestList[nxt,{0,0,1},100][[All,1]],PrimeOmega[#]==2&] (* Harvey P. Dale, Nov 17 2024 *)

Formula

a(n) = A102120(A102180(n)).

Extensions

Offset changed to 1 and more terms from Jinyuan Wang, Aug 14 2021