A133966 - OEIS

%I #11 Mar 23 2021 15:42:19

%S 3389,23929,31193,37199,37463,37547,37607,37717,37853,37907,41863,

%T 41887,41941,73331,74759,74771,77269,77797,83383,112909,114773,131321,

%U 131783,132971,134753,191231,193463,223241,223313,223331,223337,223547,231277

%N Home primes whose homeliness is 6.

%C Number of terms < 10^n: 0, 0, 0, 1, 19, 197, 1422, ... .

%e Only (118, 259, 737, 801, 1167, 3389) -> 3389, etc.

%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 = 6 - 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, A133965, A133956, A133957, A133958, A133960, A133962, A133964, A133968, A133970, A133972, A133974, A133976, A133978.

%K nonn,base

%O 1,1

%A _Robert G. Wilson v_, Sep 30 2007