OFFSET
1,2
COMMENTS
Primes in the sequence are in A030458. - Bruno Berselli, Mar 25 2015
a(n) always has an even number of digits unless n is in A103456. - Alonso del Arte, Oct 30 2019
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 1..25000
EXAMPLE
a(1) = "0,1" = 1.
a(13) = "12,13" = 1213.
MAPLE
a:= n-> parse(cat(n-1, n)):
seq(a(n), n=1..55); # Alois P. Heinz, Jul 05 2018
MATHEMATICA
nMax = 49; digitsList = IntegerDigits[Range[0, nMax]]; Table[FromDigits[Flatten[{digitsList[[n]], digitsList[[n + 1]]}]], {n, nMax - 1}] (* Alonso del Arte, Oct 24 2019 *)
Table[FromDigits[Flatten[IntegerDigits/@{n, n+1}]], {n, 0, 50}] (* Harvey P. Dale, May 16 2020 *)
PROG
(Magma) [Seqint(Intseq(n+1) cat Intseq(n)): n in [0..50]]; // Bruno Berselli, Mar 25 2015
(Python) for n in range(100): print(int(str(n)+str(n+1))) # David F. Marrs, Sep 17 2018
(Scala) val numerStrs = (0 to 49).map(Integer.toString(_)).toList
val concats = (numerStrs.dropRight(1)) zip (numerStrs.drop(1))
concats.map(x => Integer.parseInt(x._1 + x._2)) // Alonso del Arte, Oct 24 2019
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Artur Jasinski, Jan 14 2007
EXTENSIONS
More terms from Joshua Zucker, May 15 2007
STATUS
approved