The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A235472 Primes whose base 9 representation also is the base 3 representation of a prime. 1
 2, 11, 19, 83, 101, 163, 173, 739, 811, 821, 829, 911, 1549, 1559, 1621, 6563, 6581, 6661, 6733, 8111, 8191, 13933, 14753, 59069, 59141, 59779, 59797, 59951, 60589, 60607, 65629, 65701, 66359, 67079, 67231, 72271, 72353, 72901, 118189, 119557, 119657, 124669, 124823, 125399 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is part of the two dimensional array of sequences based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10. For further motivation and cross-references, see sequence A235265 which is the main entry for this whole family of sequences. Since all digits of the base 9 expansion are less than 3, this is a subsequence of A037314. LINKS Alois P. Heinz, Table of n, a(n) for n = 1..10000 EXAMPLE E.g., 17 = 21[9] and 21[3] = 7 both are prime. PROG (PARI) is(p, b=3, c=9)=vecmax(d=digits(p, c))

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified April 10 16:16 EDT 2021. Contains 342845 sequences. (Running on oeis4.)