cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A329522 Composite numbers whose sum of digits is not composite.

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%I A329522 #42 Dec 11 2023 10:50:30
%S A329522 10,12,14,16,20,21,25,30,32,34,38,49,50,52,56,58,65,70,74,76,85,92,94,
%T A329522 98,100,102,104,106,110,111,115,119,120,122,124,128,133,140,142,146,
%U A329522 148,155,160,164,166,175,182,184,188,200,201,203,205,209,210,212,214,218,221,230
%N A329522 Composite numbers whose sum of digits is not composite.
%t A329522 Select[Rest@ Complement[#, Prime@ Range@ PrimePi@ Max@ #] &@ Range@ 230, ! CompositeQ@ Total@ IntegerDigits@ # &] (* _Michael De Vlieger_, Nov 15 2019 *)
%t A329522 Select[Range[250],CompositeQ[#]&&!CompositeQ[Total[IntegerDigits[#]]]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jun 19 2021 *)
%o A329522 (PARI) lista(nn) = forcomposite(c=1, nn, my(s=sumdigits(c)); if ((s==1) || isprime(s), print1(c, ", "))); \\ _Michel Marcus_, Nov 15 2019
%o A329522 (Magma) [k:k in [2..230]| not IsPrime(k) and (IsPrime(&+Intseq(k)) or &+Intseq(k) eq 1) ]; // _Marius A. Burtea_, Feb 05 2020
%Y A329522 Cf. A046704, A104213, A141642, A228019.
%K A329522 nonn,base,easy
%O A329522 1,1
%A A329522 _Ali Adams_, Nov 15 2019