OFFSET
1,2
EXAMPLE
17, 127, 1237, 12347, 123457, ... etc. are all prime.
MAPLE
Lcat := proc(L) local a, i; a := 0 ; for i from 1 to nops(L) do a := a*10^(max(1, ilog10(op(i, L))+1))+op(i, L) ; od: RETURN(a) ; end: A109744 := proc(nmax) local a, k, n; a := [1] ; while nops(a) < nmax do n := nops(a)+1 ; k := 1; while not isprime(Lcat([op(a), k*n, 7]) ) do k := k+1 ; od ; a := [op(a), k*n] ; od: RETURN(a) ; end: op(A109744(50)) ; # R. J. Mathar, Aug 15 2007
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Aug 03 2005
EXTENSIONS
More terms from R. J. Mathar, Aug 15 2007
STATUS
approved