cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-2 of 2 results.

A102171 Iccanobirt semiprime indices (1 of 15): Indices of semiprime numbers in A102111.

Original entry on oeis.org

5, 11, 24, 33, 57, 64, 71, 72, 116, 126, 141, 174, 210, 311, 334, 370, 441, 480, 574
Offset: 1

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Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

Crossrefs

Cf. A001358, A102111, A102172-A102185.

Formula

A102111(a(n)) = A102191(n).

Extensions

a(13) from Robert Price, Nov 07 2018
Offset changed to 1 and a(14)-a(19) from Jinyuan Wang, Jul 31 2021

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

Original entry on oeis.org

4, 62, 885229, 1246986214, 6411178063, 12726051979, 107213343921600529, 2147942208584833933, 10354578286673927897, 58980651512479169892243191, 2180545853785440701368914883, 16670504896204082873702933353, 1970627022928300844150934760319, 8848738313604306954943751816182969
Offset: 1

Views

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Keywords

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
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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