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A061085
a(n) = A019550(n) / 3.
2
4, 8, 12, 16, 170, 204, 238, 272, 306, 340, 374, 408, 442, 476, 510, 544, 578, 612, 646, 680, 714, 748, 782, 816, 850, 884, 918, 952, 986, 1020, 1054, 1088, 1122, 1156, 1190, 1224, 1258, 1292, 1326, 1360, 1394, 1428, 1462, 1496, 1530, 1564, 1598, 1632, 1666
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:
A061085 := proc(n) A019550(n)/3 ; end proc: seq(A061085(n), n=1..80) ; # R. J. Mathar, Oct 10 2010
MATHEMATICA
Table[FromDigits[Join[IntegerDigits[n], IntegerDigits[2n]]]/3, {n, 50}] (* Harvey P. Dale, Aug 18 2012 *)
CROSSREFS
Cf. A019550.
Sequence in context: A175670 A355031 A194374 * A007883 A023706 A043333
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Apr 19 2001
EXTENSIONS
Offset corrected and sequence extended by R. J. Mathar, Oct 10 2010
STATUS
approved