This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A033664 Every suffix is prime. 20
 2, 3, 5, 7, 13, 17, 23, 37, 43, 47, 53, 67, 73, 83, 97, 103, 107, 113, 137, 167, 173, 197, 223, 283, 307, 313, 317, 337, 347, 353, 367, 373, 383, 397, 443, 467, 503, 523, 547, 607, 613, 617, 643, 647, 653, 673, 683, 743, 773, 797, 823, 853, 883, 907, 937, 947 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes in which repeatedly deleting the most significant digit gives a prime at every step until a single-digit prime remains. Every digit string containing the least significant digit is prime. - Amarnath Murthy, Sep 24 2003 LINKS T. D. Noe, Table of n, a(n) for n = 1..8779 Eric Weisstein's World of Mathematics, Truncatable Prime. MATHEMATICA h8pQ[n_]:=And@@PrimeQ/@Most[NestWhileList[FromDigits[Rest[ IntegerDigits[ #]]]&, n, #>0&]]; Select[Prime[Range[1000]], h8pQ] (* Harvey P. Dale, May 26 2011 *) PROG (PARI) fileO="b033664.txt"; lim=8779; v=vector(lim); v[1]=2; v[2]=3; v[3]=5; v[4]=7; j=4; write(fileO, "1 2"); write(fileO, "2 3"); write(fileO, "3 5"); write(fileO, "4 7"); p10=1; until(0, p10*=10; j0=j; for(k=1, 9, k10=k*p10; for(i=1, j0, if(j==lim, break(3)); z=k10+v[i]; if(isprime(z), j++; v[j]=z; write(fileO, j, " ", z); )))) \\ Harry J. Smith, Sep 20 2008 (Haskell) a033664 n = a033664_list !! (n-1) a033664_list = filter (all ((== 1) . a010051. read) .                            init . tail . tails . show) a000040_list -- Reinhard Zumkeller, Jul 10 2013 CROSSREFS Cf. A024785, A032437, A020994, A024770, A052023, A052024, A052025, A050986, A050987, A069866, A038680, A010051, A000040. Sequence in context: A067905 A042993 A308711 * A024785 A069866 A125772 Adjacent sequences:  A033661 A033662 A033663 * A033665 A033666 A033667 KEYWORD nonn,base,easy,nice AUTHOR EXTENSIONS More terms from Erich Friedman STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 14 02:29 EDT 2019. Contains 327995 sequences. (Running on oeis4.)