A097208 - OEIS

%I #15 Dec 15 2017 17:36:45

%S 40,24,19,17,16,10,23,21,92,313,155,551,2575,757,13537,5525,35133,

%T 33953,332975,355573,3157535,1571573,2732737,3775555,5737571,37332775

%N a(n) is the least k such that A098598(k) = n.

%C a(27) = 75787577. No more terms < 10^8. - _David Wasserman_, Dec 27 2007

%e a(3)=17 because it is the least number that contains 3 primes in the sequence 1,7,8,15,23,38,61,99,160,259.

%t f[n_] := Block[{id = IntegerDigits[n], t = Floor[ Log[10, n] + 1], b}, Do[ b[i] = id[[i]], {i, t}]; b[i_] := b[i] = Plus @@ Table[b[i - j], {j, t}]; k = t + 1; While[b[k] < n^2, k++ ]; Count[ PrimeQ[ Table[b[i], {i, k - 1}]], True]]; t = Table[0, {50}]; Do[c = f[n]; If[ t[[c + 1]] == 0, t[[c + 1]] = n; Print[c, " = ", n]], {n, 10, 12000000}]; t (* _Robert G. Wilson v_, Oct 07 2004 *)

%Y Cf. A098598.

%K base,nonn,more

%O 0,1

%A _Jason Earls_, Sep 17 2004

%E Corrected and extended by _Robert G. Wilson v_, Oct 07 2004

%E a(25), a(27) and better definition from _David Wasserman_, Dec 27 2007