A095958 Twin prime pairs concatenated in decimal representation.

35, 57, 1113, 1719, 2931, 4143, 5961, 7173, 101103, 107109, 137139, 149151, 179181, 191193, 197199, 227229, 239241, 269271, 281283, 311313, 347349, 419421, 431433, 461463, 521523, 569571, 599601, 617619, 641643, 659661

Offset: 1

Author

Reinhard Zumkeller, Jul 14 2004

Keywords

• nonn
• base

Comments

a(n) mod 3 = 0 for n>1, proof: A007953(a(n)) = 2*A007953(A001359(n)+1) and A007953(A001359(n)) mod 3 = 2 for n>1, therefore A007953(a(n)) mod 3 = 0.

Examples

			29 = A001359(5), 29 + 2 = 31 = A006512(5): a(5) = 2931.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A045533, A001359, A006512.

Cf. A077800, subsequence of A045533.

Programs

Haskell

a095958 n = a095958_list !! (n-1)
a095958_list = f $ map show a077800_list :: [Integer] where
   f (t:t':ts) = read (t ++ t') : f ts
-- Reinhard Zumkeller, Apr 20 2012

Magma

[Seqint( Intseq(NthPrime(n+1)) cat Intseq(NthPrime(n)) ): n in [1..150 ]| NthPrime(n+1)-NthPrime(n) eq 2 ]; // Marius A. Burtea, Mar 21 2019

Mathematica

concat[{a_,b_}]:=FromDigits[Flatten[IntegerDigits/@{a,b}]]; concat/@ Select[Partition[ Prime[ Range[150]],2,1],#[[2]]-#[[1]]==2&] (* Harvey P. Dale, Apr 20 2012 *)