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A133970 Home primes whose homeliness is 8. 12

%I #11 Mar 23 2021 15:42:02

%S 3761,13367,31397,132953,233743,233911,313829,333857,333923,337397,

%T 337487,337661,337907,357727,370451,373753,374159,375407,375979,

%U 379433,379859,383557,397673,397751,397829,399241,409823,473659,616789,733331

%N Home primes whose homeliness is 8.

%C Number of terms < 10^n: 0, 0, 0, 1, 3, 33, 318, ... .

%t 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}];

%t 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]

%Y Cf. A037274, A118756, A133969, A133956, A133957, A133958, A133960, A133962, A133964, A133966, A133968, A133972, A133974, A133976, A133978.

%K nonn,base

%O 1,1

%A _Robert G. Wilson v_, Sep 30 2007

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)