A179908 First appearance of n in A039996: Primes embedded in prime(n).

1, 6, 9, 30, 33, 203, 270, 220, 1476, 1368, 2638, 10561, 10726, 18926, 87984, 86693, 101294, 170447, 734638, 749502, 1503095, 6475615, 3131428, 7364000, 6504583, 27508889, 56295291, 66084700, 98097954

Offset: 1

Author

Robert G. Wilson v, Aug 01 2010

Keywords

• nonn
• base

Crossrefs

Cf. A039996, A079397, A178596, A178597.

Programs

Mathematica

f[n_] := Block[ {id = IntegerDigits@n}, len = Length@ id - 1; Count[ PrimeQ@ Union[ FromDigits@# & /@ Flatten[ Table[ Partition[ id, k, 1], {k, len}], 1]], True] + 1]; t = Table[0, {30}]; p = 2; While[p < 2*10^9, a = f@p; If[ t[[a]] == 0, pp = PrimePi@p; t[[a]] = pp; Print[{a, p, pp}]]; p = NextPrime@p]; t