A194954 Slowest increasing sequence of primes such that a(1)=2, a(n)-a(n-1) is multiple of A000120(n-1).

2, 3, 5, 7, 11, 13, 17, 23, 29, 31, 37, 43, 47, 53, 59, 67, 71, 73, 79, 97, 101, 107, 113, 137, 139, 151, 157, 173, 179, 191, 199, 229, 233, 239, 241, 271, 277, 283, 307, 311, 313, 331, 337, 349, 367, 379, 383, 433, 439, 457, 463, 467, 479, 487, 491, 521, 557

Offset: 1

Author

Vladimir Shevelev, Sep 06 2011

Keywords

• nonn
• base

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000040, A000120, A194955.

Programs

Maple

A194954 := proc(n)
        option remember;
        local p;
        if n = 1 then
                2;
        else
                p := nextprime(procname(n-1)) ;
                while (p-procname(n-1)) mod A000120(n-1) <> 0 do
                        p := nextprime(p);
                end do;
                p ;
        end if;
end proc:
seq(A194954(n),n=1..80) ; # R. J. Mathar, Sep 20 2011

Mathematica

a[1] = 2; a[n_] := a[n] = Module[{k = a[n - 1], s = DigitCount[n - 1, 2, 1]}, k += s; While[! PrimeQ[k], k += s]; k]; Array[a, 50] (* Amiram Eldar, Jul 25 2023 *)

Extensions

Corrected by R. J. Mathar, Sep 20 2011