A109309 Larger emirps (primes whose digit reversal is a lesser prime).

31, 71, 73, 97, 311, 701, 733, 743, 751, 761, 907, 937, 941, 953, 967, 971, 983, 991, 1201, 1301, 1321, 1511, 1601, 1741, 1811, 1831, 1901, 3011, 3121, 3191, 3203, 3221, 3251, 3271, 3301, 3371, 3391, 3433, 3511, 3541, 3571, 3613, 3643, 3733, 3803, 3821

Offset: 1

Author

Zak Seidov, Jun 25 2005

Keywords

• base
• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A006567 Emirps (primes whose digit reversal is a different prime), A109308 Lesser emirps (primes whose digit reversal is a larger prime).

Programs

Mathematica

dr[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Select[Prime[Range[1000]], PrimeQ[dr[ # ]]&&dr[ # ]<#&]
Select[Prime[Range[600]],PrimeQ[IntegerReverse[#]]&&#>IntegerReverse[#]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 23 2020 *)