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A095958
Twin prime pairs concatenated in decimal representation.
8
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
1,1
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.
LINKS
EXAMPLE
29 = A001359(5), 29 + 2 = 31 = A006512(5): a(5) = 2931.
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 *)
PROG
(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
CROSSREFS
Cf. A077800, subsequence of A045533.
Sequence in context: A351095 A267738 A219806 * A244057 A219457 A343099
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Jul 14 2004
STATUS
approved