This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A045533 #38 Feb 17 2024 10:31:38 %S A045533 23,35,57,711,1113,1317,1719,1923,2329,2931,3137,3741,4143,4347,4753, %T A045533 5359,5961,6167,6771,7173,7379,7983,8389,8997,97101,101103,103107, %U A045533 107109,109113,113127,127131,131137 %N A045533 Concatenate the n-th and (n+1)st prime. %H A045533 Reinhard Zumkeller, <a href="/A045533/b045533.txt">Table of n, a(n) for n = 1..10000</a> %F A045533 a(n) = prime(n)*(10^floor(log_10(prime(n+1)))+1) + prime(n+1). - _Conner L. Delahanty_, May 10 2014 %t A045533 #[[1]]*10^IntegerLength[#[[2]]]+#[[2]]&/@Partition[Prime[Range[40]],2,1] (* _Harvey P. Dale_, Jun 06 2015 *) %o A045533 (Haskell) %o A045533 a045533 n = a045533_list !! (n-1) %o A045533 a045533_list = f $ map show a000040_list :: [Integer] where %o A045533 f (t:ts@(t':_)) = read (t ++ t') : f ts %o A045533 -- _Reinhard Zumkeller_, Apr 20 2012 %o A045533 (PARI) a(n) = eval(concat(Str(prime(n)), Str(prime(n+1)))); \\ _Michel Marcus_, May 11 2014 %o A045533 (Magma) [Seqint(Intseq(NthPrime(n+1)) cat Intseq(NthPrime(n))): n in [1..50 ] ]; // _Marius A. Burtea_, Mar 21 2019 %Y A045533 Cf. A077800, A095958 (subsequence), A030461 (primes). %K A045533 nonn,base %O A045533 1,1 %A A045533 _N. J. A. Sloane_, Dec 11 1999 %E A045533 Offset changed to 1, in agreement with (almost?) all references to this sequence, by _M. F. Hasler_