OFFSET
1,1
LINKS
Jinyuan Wang, Table of n, a(n) for n = 1..10000
EXAMPLE
21 is a term because it is the concatenation of 2 (a prime) and the 2nd nonnegative nonprime integer 1 (which is odd);
1725 is a term because it is the concatenation of 17 (a prime) and the 17th nonnegative nonprime integer 25 (which is odd).
MAPLE
cat2 := proc(a, b) dgsb := max(1, ilog10(b)+1) ; a*10^dgsb+b ; end proc:
A155740 := proc(n) p := ithprime(n) ; c := A141468(p) ; if type(c, 'odd') then cat2(p, c) ; printf("%d, ", %) ; end if; return ; end proc:
seq(A155740(n), n=1..120) ; # R. J. Mathar, May 15 2010
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
Juri-Stepan Gerasimov, Jan 26 2009
EXTENSIONS
Corrected (1321 removed, all terms >= 200000 corrected) by R. J. Mathar, May 15 2010
Name and Example section edited by Jon E. Schoenfield, Feb 14 2019
STATUS
approved