OFFSET
1,1
EXAMPLE
For n = 72, the smallest single or isolated number in the sequence 1, 73, 145, 217, 289, 361, 433, 505, 577, ... is 577, so a(72) = 577.
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Nov 15 2009
EXTENSIONS
Corrected (a(2) replaced by 23, a(3) inserted, 113 replaced by 97, 337 by 97, 257 by 97 etc.) by R. J. Mathar, May 30 2010
STATUS
approved