Re^2: Error-finding program

[Richard Mathar]

> From seqfan-owner at ext.jussieu.fr  Wed Oct 25 21:07:37 2006
> Return-Path: <seqfan-owner at ext.jussieu.fr>
> To: seqfan at ext.jussieu.fr
> Subject: Re: Error-finding program
> Date: Wed, 25 Oct 2006 15:05:48 -0400
> ...
> A117504 There's something seriously wrong here, but I don't know just 
> what.
> ...

This is what I get for A117504, monotonic as it must be:

a := [37, 137, 151, 173, 409, 467, 503, 677, 937, 1091, 1153, 1229, 1303, 1409,

    1453, 1471, 1531, 2137, 2221, 2251, 2393, 2503, 2593, 2633, 2671, 2797,

    2837, 3001, 3023, 3089, 3163]

using in Maple

Digits := 30 ;
A117504 := proc(nmax)
        local a,pisum,p ;
        a := [] ;
        pisum := 0 ;
        p :=1 ;
        while nops(a) <=nmax do
                while true do
                        pisum := pisum+floor(Pi*ithprime(p)) ;
                        p := p+1 ;
                        if isprime(pisum) then
                                a := [op(a),ithprime(p-1)] ;
                                break ;
                        fi ;
                od :
        od :
        RETURN(a) ;
end:
a := A117504(30) ;

I submitted the Maple program of the corresponding A117503 (which
is correct) already to the OEIS; everybody is free to do the same
with the artwork above.... 

Explanation of the erroneous version of A117504: it contains up to n=10 the primes,
and for n>=11 the prime indices, so instead of 191 we need to have
1153 which is the 191th prime, instead of 201 the 201st prime etc.

RJM