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A079470 Primes with prime inventory number (as in A063850). 0

%I #2 Feb 11 2014 19:05:41

%S 3,7,17,23,113,127,131,137,193,199,223,233,271,311,313,331,359,367,

%T 431,433,439,463,479,499,503,523,587,607,641,677,691,733,773,797,809,

%U 821,823,829,853,997,1009,1069,1123,1129,1187,1213,1217,1223,1231,1277,1291

%N Primes with prime inventory number (as in A063850).

%H Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_207.htm">TheInventory Sequences and Self-Inventoried Numbers</a>

%e The prime 127 has inventory number 111217 (one "1", one "2", one "7"), which is also prime. Hence 127 belongs to the sequence.

%t g[n_] := Module[{seen, r, d, l, i, t}, seen = {}; r = {}; d = IntegerDigits[n]; l = Length[d]; For[i = 1, i <= l, i++, t = d[[i]]; If[ ! MemberQ[seen, t], r = Join[r, IntegerDigits[Count[d, t]]]; r = Join[r, {t}]; seen = Append[seen, t]]]; FromDigits[r]]; s = {}; For[j = 1, j <= 10^3, j++, temp = Prime[j]; If[PrimeQ[g[temp]], s = Append[s, temp]]]; s

%Y Cf. A063850.

%K base,easy,nonn

%O 1,1

%A _Joseph L. Pe_, Jan 15 2003

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Last modified May 9 23:14 EDT 2024. Contains 372354 sequences. (Running on oeis4.)