A102192 Iccanobirt semiprimes (2 of 15): Semiprime numbers in A102112.

4, 62, 885229, 1246986214, 6411178063, 12726051979, 107213343921600529, 2147942208584833933, 10354578286673927897, 58980651512479169892243191, 2180545853785440701368914883, 16670504896204082873702933353, 1970627022928300844150934760319, 8848738313604306954943751816182969

Offset: 1

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

• nonn
• less
• base

Crossrefs

Cf. A001358, A102112, A102191-A102205.

Programs

Mathematica

nxt[{a_,b_,c_}]:={b,c,a+IntegerReverse[b]+c};Select[NestList[nxt,{0,0,1},100][[All,1]],PrimeOmega[#]==2&] (* Harvey P. Dale, Jul 11 2021 *)

Formula

a(n) = A102112(A102172(n)).

Extensions

Offset changed to 1 and more terms from Jinyuan Wang, Aug 08 2021