OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..369
EXAMPLE
a(3) = 123 +321 = 444,a(10) = 12345678910 + 10987654321 = 23333333231.
MATHEMATICA
Table[With[{c1=FromDigits[Flatten[IntegerDigits/@Range[n]]], c2= FromDigits[ Flatten[ IntegerDigits/@Range[n, 1, -1]]]}, c1+c2], {n, 20}] (* Harvey P. Dale, Jul 03 2020 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 24 2002
EXTENSIONS
More terms from Sascha Kurz, Jan 04 2003
STATUS
approved