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A133970
Home primes whose homeliness is 8.
12
3761, 13367, 31397, 132953, 233743, 233911, 313829, 333857, 333923, 337397, 337487, 337661, 337907, 357727, 370451, 373753, 374159, 375407, 375979, 379433, 379859, 383557, 397673, 397751, 397829, 399241, 409823, 473659, 616789, 733331
OFFSET
1,1
COMMENTS
Number of terms < 10^n: 0, 0, 0, 1, 3, 33, 318, ... .
MATHEMATICA
lst = {}; f[n_] := FromDigits@ Flatten[ IntegerDigits@ Table[ #[[1]], {#[[2]]}] & /@ FactorInteger@n, 2]; h[n_] := NestWhileList[f@# &, n, !PrimeQ@# &, 1, 28]; Do[p = h[n][[ -1]]; If[ PrimeQ@p && p < 10^7 && p != n, Print[{n, p}]; AppendTo[lst, p]], {n, 2, 1000}];
d = 8 - 2; lsu = {}; Do[ If[ lst[[n]] == lst[[n + d]] && lst[[n - 1]] != lst[[n]] && lst[[n]] != lst[[n + d + 1]], AppendTo[lsu, lst[[n]]]], {n, 188004 - d - 1}]; Take[Union@ lsu, 35]
KEYWORD
nonn,base
AUTHOR
Robert G. Wilson v, Sep 30 2007
STATUS
approved