OFFSET
1,1
COMMENTS
a(n) is divisible by 4 for n >= 2. - Michel Marcus, Sep 21 2015
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Sylvester Smith, A Set of Conjectures on Smarandache Sequences, Bulletin of Pure and Applied Sciences, (Bombay, India), Vol. 15 E (No. 1), 1996, pp. 101-107.
MAPLE
a:=n->n*10^floor(log10(4*n)+1)+4*n: seq(a(n), n=1..50); # Muniru A Asiru, Jun 23 2018
MATHEMATICA
Table[FromDigits[Join[IntegerDigits[n], IntegerDigits[4n]]], {n, 50}] (* Harvey P. Dale, May 11 2011 *)
nxt[n_]:=Module[{idn=IntegerDigits[n], idn4=IntegerDigits[4n]}, FromDigits[Join[idn, idn4]]]; Array[nxt, 100] (* Vincenzo Librandi, Feb 04 2014 *)
PROG
(Magma) [Seqint(Intseq(4*n) cat Intseq(n)): n in [1..50]]; // Vincenzo Librandi, Feb 04 2014
(PARI) a(n) = eval(Str(n, 4*n)); \\ Michel Marcus, Sep 21 2015
CROSSREFS
KEYWORD
nonn,base,less,easy
AUTHOR
R. Muller
STATUS
approved