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Search: id:A133972
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| A133972 |
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Home primes whose homeliness is 9. |
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+0
13
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| 178069, 229751, 313613, 313739, 317741, 317903, 337457, 337853, 352489, 374587, 375743, 375997, 379103, 379187, 379397, 379997, 389971, 719239, 733391, 742283, 1128901, 1143113, 1148593, 1392143, 1911319, 2231051, 2331997, 2333329
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Number of terms < 10^n: 0, 0, 0, 0, 0, 20, 146, ....
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MATHEMATICA
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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 = 9 - 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]
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CROSSREFS
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Cf. A037274, A118756, A133971, A133956, A000014, A133958, A133960, A133962, A133964, A133966, A133968, A133970, A133974, A133976, A133978.
Sequence in context: A017435 A017567 A081867 this_sequence A056748 A060232 A133541
Adjacent sequences: A133969 A133970 A133971 this_sequence A133973 A133974 A133975
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 30 2007
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