A089702 a(1) = 2 then primes in nondecreasing order such that every concatenation is prime.

2, 3, 3, 3, 3, 23, 43, 59, 67, 83, 199, 239, 421, 569, 613, 1307, 2017, 2129, 2467, 2741, 2953, 3011, 3319, 3413, 3607, 3617, 5449, 6917, 7333, 7529, 8389, 10211, 10357, 12641, 12703, 15077, 17107, 21341, 21799, 22469, 32911, 33587, 33613, 33647

Offset

0,1

Links

Table of n, a(n) for n=0..43.

Example

2,23,233,2333,23333,2333323 etc. are primes.

Maple

ds:=proc(s) local j: RETURN(add(s[j]*10^(j-1), j=1..nops(s))):end: a:=[2]: k:=1: for n from 1 to 50 do l:=nops(a): for i from k do p:=ithprime(i): if isprime(ds([op(convert(p, base, 10)), seq(op(convert(a[l-j], base, 10)), j=0..l-1)])) then a:=[op(a), p]: k:=i: break fi od od: op(a); # C. Ronaldo

Crossrefs

Cf. A089703.

Sequence in context: A069603 A033679 A051670 * A089336 A089335 A088093

Adjacent sequences: A089699 A089700 A089701 * A089703 A089704 A089705

Keyword

base,nonn

Author

Amarnath Murthy, Nov 10 2003

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004

Status

approved