[seqfan] Re: Fwd: Right truncatable primes

[Robert Gerbicz]

2008/10/31 Martin Fuller <martin_n_fuller at btinternet.com>

> Would a kind SeqFan confirm the value of A076623(12) for me?  OEIS lists
> the result as 170051 and I calculate 170053.
>
> A076623 Total number of left truncatable primes (without zeros) in base n.
>
> Martin Fuller


By the following  PARI  code I've gotten f(12)=170053.

f(b)=ct=0;A=[0];n=-1;L=1;while(L,n++;B=vector(L*b);M=0;\
for(i=1,L,for(j=1,b-1,x=A[i]+j*b^n;if(isprime[x],M++;B[M]=x;ct++)));\
L=M;A=vector(L,i,B[i]));return(ct)