A348370 Numbers k such that pi(reversal(prime(k))) = reversal(k). Ignore leading 0's.

1, 2, 3, 4, 5, 12, 21, 86, 235, 8114118, 535252535

Offset

1,2

Comments

535252535 is a term (not necessarily the next one), so it seems this sequence is a supersequence of A069469.

From Martin Ehrenstein, Nov 06 2021: (Start)

Equivalently: Numbers k such that prime(reversal(k)) <= reversal(prime(k)) < prime(reversal(k)+1). Ignore leading 0's.

Thus A069469 is indeed a subsequence.

a(12) > 10^10. (End)

Links

Table of n, a(n) for n=1..11.

Mathematica

Select[Range[300], PrimePi[IntegerReverse[Prime[#]]]==IntegerReverse[#]&]

Crossrefs

Cf. A000040, A000720, A004086, A069469.

Sequence in context: A117577 A109849 A007662 * A069469 A175807 A165303

Adjacent sequences: A348367 A348368 A348369 * A348371 A348372 A348373

Keyword

nonn,base,more

Author

Ivan N. Ianakiev, Oct 15 2021

Extensions

a(11) verified by Martin Ehrenstein, Nov 06 2021

Status

approved