OFFSET
1,1
COMMENTS
The concatenated composites are A129808, the initial 1 removed.
FORMULA
a(n) = A129808(prime(n)+1).
MAPLE
a129808 := [1 ] : for n from 4 to 400 do if not isprime(n) then a129808 := [op(a129808), op(ListTools[Reverse](convert(n, base, 10))) ] ; fi; od:
for n from 1 do p := ithprime(n) ; printf("%d, ", op(p+1, a129808) ) ; od: # R. J. Mathar, Aug 03 2009
MATHEMATICA
nn=700; With[{c=Flatten[IntegerDigits/@Complement[Range[4, nn], Prime[Range[ PrimePi[nn]]]]]}, Flatten[Table[Take[c, {n, n}], {n, Prime[Range[ PrimePi[ nn]]]}]]] (* Harvey P. Dale, Nov 22 2013 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Juri-Stepan Gerasimov, Jan 11 2009
EXTENSIONS
Edited and corrected by R. J. Mathar, Aug 03 2009
STATUS
approved