OFFSET
1,1
LINKS
Amarnath Murthy, Some propositions on Smarandache n2n sequence, Smarandache Notions Journal, Digital Library of Science, p 126
Felice Russo, A set of new Smarandache Functions, Sequences and conjectures in number theory, Smarandache Notions Journal, Digital Library of Science, (2000)
FORMULA
a(n) = one-third of the number obtained by concatenating n with 2n.
EXAMPLE
a(8) = 272 = 816/3, where 816 is 8 concatenated with 16.
MAPLE
cat2 := proc(a, b) dgsb := max(1, ilog10(b)+1) ; a*10^dgsb+b ; end proc:
A019550 := proc(n) cat2(n, 2*n) ; end proc:
MATHEMATICA
Table[FromDigits[Join[IntegerDigits[n], IntegerDigits[2n]]]/3, {n, 50}] (* Harvey P. Dale, Aug 18 2012 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Apr 19 2001
EXTENSIONS
Offset corrected and sequence extended by R. J. Mathar, Oct 10 2010
STATUS
approved