OFFSET
1,1
COMMENTS
A089392 has no members with 10, 11, or 12 digits. It is unlikely that it has any with more than 12 digits. - David Wasserman, Sep 15 2005
Giovanni Resta has checked this up to 16 digits. Indeed 5391391551358 and 97393713331910 are the only 13- resp. 14-digit numbers (not primes) with this property, i.e., in A252996. See Carlos Rivera's puzzle page for a probabilistic argument concerning the finiteness. - M. F. Hasler, Dec 25 and Dec 28 2014
LINKS
C. Rivera, Puzzle 401. Magnanimous primes, 2007.
MAPLE
with(combinat): ds:=proc(s) local j: RETURN(add(s[j]*10^(j-1), j=1..nops(s))):end: for d from 1 to 6 do sch:=[seq([1, op(i), d+1], i=[[], seq([j], j=2..d)])]: for n from 10^d-1 by -1 to 10^(d-1) do sn:=convert(n, base, 10): fl:=0: for s in sch do m:=add(j, j=[seq(ds(sn[s[i]..s[i+1]-1]), i=1..nops(s)-1)]): if not isprime(m) then fl:=1: break fi od: if fl=0 then printf("%d, ", n):break fi od od: # C. Ronaldo
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Amarnath Murthy, Nov 10 2003
EXTENSIONS
More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 25 2004
3 more terms from David Wasserman, Sep 15 2005
Definition edited and a(10..16) = 0 added by M. F. Hasler, Dec 28 2014
STATUS
approved