OFFSET
1,2
EXAMPLE
a(34) = 34*45/2 = 765. a(129) = 129*230/2 =14835
MATHEMATICA
Table[n/2 FromDigits[(IntegerDigits[n]+1)/.(10->0)], {n, 60}] (* Harvey P. Dale, Jul 08 2011 *)
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Amarnath Murthy, Feb 15 2002
EXTENSIONS
More terms from Sascha Kurz, Mar 28 2002
Corrected definition -- Harvey P. Dale, Jul 08 2011
STATUS
approved