A067087 Concatenation of n-th prime and its reverse.

22, 33, 55, 77, 1111, 1331, 1771, 1991, 2332, 2992, 3113, 3773, 4114, 4334, 4774, 5335, 5995, 6116, 6776, 7117, 7337, 7997, 8338, 8998, 9779, 101101, 103301, 107701, 109901, 113311, 127721, 131131, 137731, 139931, 149941, 151151, 157751

Offset: 1

Author

Amarnath Murthy, Jan 07 2002

Keywords

• easy
• nonn
• base

Comments

Every term of the sequence is divisible by 11.

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A056524.

Programs

Mathematica

Table[ ToExpression[ StringJoin[ ToString[Prime[n]], StringReverse[ ToString[ Prime[n]]]]], {n, 1, 40} ]
#*10^IntegerLength[#]+IntegerReverse[#]&/@Prime[Range[50]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 11 2017 *)

PARI

a(n) = { my(d=digits(prime(n))); fromdigits(concat(d,Vecrev(d))) } \\ Harry J. Smith, May 13 2010

Formula

a(n) = A056524(prime(n)). - Andrew Howroyd, Dec 07 2024

Extensions

More terms from Robert G. Wilson v, Jan 09 2002