A103443 Largest left-truncatable prime in base n (decimal expansion).
23, 4091, 7817, 4836525320399, 817337, 14005650767869, 1676456897, 357686312646216567629137, 2276005673, 13092430647736190817303130065827539, 812751503, 615419590422100474355767356763
Offset: 3
Links
- Martin Fuller, Table of n, a(n) for n = 3..29
- I. O. Angell, and H. J. Godwin, On Truncatable Primes Math. Comput. 31, 265-267, 1977. (See also Sloane link below)
- James Grime and Brady Haran, 357686312646216567629137, Numberphile video (2018).
- Martin Renner, Table of n, a(n) for n = 3..53 (with some question marks). Corrected and expanded by Hans Havermann, Jan 25 2014.
- N. J. A. Sloane, The Angell-Godwin table of initial terms of A023107 and A103443
- Eric Weisstein's World of Mathematics, Truncatable Prime.
- Index entries for sequences related to truncatable primes
Programs
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PARI
a(n)=my(v=primes(primepi(n-1)),u,t,b=1,best); while(#v, best=vecmax(v); b*=n; u=List(); for(i=1,#v,for(k=1,n-1,if(isprime(t=v[i]+k*b), listput(u,t)))); v=Vec(u)); best \\ Charles R Greathouse IV, Feb 05 2013
Extensions
Base-14 entry corrected by Hans Havermann, May 30 2011
Corresponding entry in a-file corrected by N. J. A. Sloane, Jun 02 2011
a-file corrected and expanded by Hans Havermann, Jan 25 2014