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 A096237 Number of n-digit base-4 deletable primes. 0
 2, 3, 9, 26, 75, 213, 615, 1853, 5854, 18664, 61248, 205300, 698575, 2409598, 8408050 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A prime p is a base-b deletable prime if when written in base b it has the property that removing some digit leaves either the empty string or another deletable prime. "Digit" means digit in base b. Deleting a digit cannot leave any leading zeros in the new string. For example, deleting the 2 in 2003 to obtain 003 is not allowed. LINKS MATHEMATICA b = 4; a = {2}; d = {2, 3}; For[n = 2, n <= 8, n++,   p = Select[Range[b^(n - 1), b^n - 1], PrimeQ[#] &];   ct = 0;   For[i = 1, i <= Length[p], i++,    c = IntegerDigits[p[[i]], b];    For[j = 1, j <= n, j++,     t = Delete[c, j];     If[t[[1]] == 0, Continue[]];     If[MemberQ[d, FromDigits[t, b]], AppendTo[d, p[[i]]]; ct++;      Break[]]]];   AppendTo[a, ct]]; a (* Robert Price, Nov 12 2018 *) CROSSREFS Cf. A080608, A080603, A096235-A096246. Sequence in context: A056198 A143742 A038523 * A177928 A057231 A178028 Adjacent sequences:  A096234 A096235 A096236 * A096238 A096239 A096240 KEYWORD nonn,base,more AUTHOR Michael Kleber, Feb 28 2003 EXTENSIONS 10 more terms from Ryan Propper, Jul 19 2005 STATUS approved

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Last modified December 15 13:27 EST 2018. Contains 318149 sequences. (Running on oeis4.)