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.

A084995 Numbers which can be written as the product of two different primes and the sum of digits is also prime.

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%I A084995 #10 Feb 28 2022 19:07:39
%S A084995 14,21,34,38,58,65,74,85,94,106,111,115,119,122,133,142,146,155,166,
%T A084995 201,203,205,209,214,218,221,247,254,265,274,278,287,298,302,319,326,
%U A084995 335,346,355,362,371,377,382,386,391,395,403,407,427,445,454,458,469,478,481,485
%N A084995 Numbers which can be written as the product of two different primes and the sum of digits is also prime.
%H A084995 Andrew Howroyd, <a href="/A084995/b084995.txt">Table of n, a(n) for n = 1..1000</a>
%F A084995 Intersection of A028834 and A006881. - _Andrew Howroyd_, Jan 05 2020
%e A084995 E.g., 14 = 7*2 and 1+4 = 5 is also prime.
%t A084995 Module[{nn=60},Select[Union[Times@@@Subsets[Prime[Range[nn]],{2}]],PrimeQ[ Total[ IntegerDigits[#]]]&&#<=2Prime[nn]&]] (* _Harvey P. Dale_, Feb 28 2022 *)
%o A084995 (PARI) is(n)={bigomega(n)==2 && !issquare(n) && isprime(sumdigits(n))}
%o A084995 select(is, [1..500]) \\ _Andrew Howroyd_, Jan 05 2020
%Y A084995 Cf. A006881, A028834, A108606.
%K A084995 nonn,base
%O A084995 1,1
%A A084995 Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 30 2003
%E A084995 Terms a(14) and beyond from _Andrew Howroyd_, Jan 05 2020