1,1

Emirps that yield other emirps when turned upside down. - Lekraj Beedassy, Apr 03 2009

Invertible primes whose reversals are also invertible primes. - Lekraj Beedassy, Apr 04 2009

All terms must begin and end with a one. - T. D. Noe, Apr 21 2014

A term has to include 6 or 9. The concatenation of first n = 809 bemirp 10611091...11688981911 is a prime with 8143 digits being the smallest one for n > 1. There isn't a bemirp < 10^15 with a bemirp index (over all primes). Bemirps such that 4 associated primes are all Sophie Germain primes are 1161880189181, 1191880186181, 1819810881611, 1816810881911, ... . - Metin Sariyar, Mar 06 2020

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000 (first 468 terms from T. D. Noe)

Giovanni Resta, bemirps

upDown[0] = 0; upDown[1] = 1; upDown[6] = 9; upDown[8] = 8; upDown[9] = 6; fQ[p_] := Module[{revP, upDownP, revUpDownP}, If[Intersection[{2, 3, 4, 5, 7}, Union[IntegerDigits[p]]] != {}, False, revP = FromDigits[Reverse[IntegerDigits[p]]]; upDownP = FromDigits[upDown /@ IntegerDigits[p]]; revUpDownP = FromDigits[Reverse[IntegerDigits[upDownP]]]; p != revP && p != upDownP && p != revUpDownP && PrimeQ[revP] && PrimeQ[upDownP] && PrimeQ[revUpDownP]]]; t = {}; nn = 6; Do[p = 10^n; While[p < 2*10^n, p = NextPrime[p]; If[fQ[p], AppendTo[t, p]]], {n, nn}]; t (* T. D. Noe, Apr 21 2014 *)

Cf. A003684, A006567, A007628, A046732, A048051, A048052, A048053, A048054.

Sequence in context: A276355 A294164 A335731 * A020374 A142822 A122712

Adjacent sequences: A048892 A048893 A048894 * A048896 A048897 A048898

base,nonn,nice

More terms from David W. Wilson

approved