A102174 Iccanobirt semiprime indices (4 of 15): Indices of semiprime numbers in A102114.

5, 11, 18, 33, 35, 37, 43, 44, 56, 63, 93, 148, 175, 176, 204, 288, 317

Offset

1,1

Links

Table of n, a(n) for n=1..17.

Formula

A102114(a(n)) = A102194(n).

Mathematica

nxt[{a_, b_, c_}]:={b, c, IntegerReverse[c]+b+a}; Flatten[Position[ NestList[ nxt, {0, 0, 1}, 200][[All, 1]], _?(PrimeOmega[#]==2&)]]-1 (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 16 2018 *)

Crossrefs

Cf. A001358, A102114, A102171-A102185, A102194.

Sequence in context: A365417 A140697 A048253 * A140515 A056996 A102184

Adjacent sequences: A102171 A102172 A102173 * A102175 A102176 A102177

Keyword

nonn,more,less,base

Author

Jonathan Vos Post and Ray Chandler, Dec 31 2004

Extensions

a(15) from Robert Price, Nov 08 2018

Offset changed to 1 and a(16)-a(17) from Jinyuan Wang, Aug 10 2021

Status

approved