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A133964
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Home primes whose homeliness is 5.
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12
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773, 1129, 3137, 3251, 3593, 3797, 7541, 7853, 23167, 23557, 23719, 23743, 23773, 23971, 31973, 33191, 33331, 33769, 33863, 37307, 37573, 37691, 37997, 39733, 39929, 47797, 53101, 61613, 67349, 67709, 71129, 71171, 71443, 71719, 73181
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Number of terms < 10^n: 0, 0, 1, 8, 44, 417, 3299, ....
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EXAMPLE
| Only (10, 25, 55, 511, 773) -> 773, etc.
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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 = 5 - 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, 45]
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CROSSREFS
| Cf. A037274, A118756, A133963, A133956, A000014, A133958, A133960, A133962, A133966, A133968, A133970, A133972, A133974, A133976, A133978.
Sequence in context: A045078 A114543 A133963 * A033919 A055521 A077077
Adjacent sequences: A133961 A133962 A133963 * A133965 A133966 A133967
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 30 2007
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