A174211 Prime numbers in A055143.

3, 13, 15168688709231, 485398038695407, 7952761465985556761, 1093019213097503446341283921459, 86134299614492097006118364066622168655354924541642968442774111281671429433861154475887035336602787171493636213948843751229781471990372187234719413

Offset

1,1

Comments

Next terms have 145, 196, 242, 519, ... digits.

Links

Table of n, a(n) for n=1..7.

Example

Base 2: 1,10,11,100,101,110,111,1000,...; first 2 digits: 11 -> 3; first 4 digits: 1101 -> 13.

Maple

P:=proc(i) local a, b, j, k, len, n; j:=0; for n from 1 by 1 to i do a:=convert(n, binary); len:=length(a); while len>0 do len:=len-1; b:=trunc(10*frac(trunc(a/10^len)/10)); j:=j*10; if b=1 then j:=j+1; k:=convert(j, decimal, binary); if isprime(k) then print(k); fi; fi; od; od; end: P(500);

Crossrefs

Sequence in context: A271393 A087345 A048756 * A264611 A157323 A016549

Adjacent sequences: A174208 A174209 A174210 * A174212 A174213 A174214

Keyword

nonn,base

Author

Paolo P. Lava & Giorgio Balzarotti, Mar 16 2010

Status

approved