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A320879 Primes such that iteration of A062028 (n + its digit sum) yields 7 primes in a row.

%I A320879 #26 Feb 10 2019 05:19:19
%S A320879 286330897,10858338851,12869802851,15845166851,29837412851,
%T A320879 45480846799,56676324799,56676324863,68105187851,73915118861,
%U A320879 114737845853,129282912851,154648223809,155738371853,207036953861,271077075851,358515148853,373169411809,373169411861,395705343799
%N A320879 Primes such that iteration of A062028 (n + its digit sum) yields 7 primes in a row.
%C A320879 The first 15 terms are immediately calculated from A320878(1..200) using the formula.
%H A320879 Lars Blomberg, <a href="/A320879/b320879.txt">Table of n, a(n) for n = 1..445</a> (Terms < 10^14)
%H A320879 Carlos Rivera, <a href="http://www.primepuzzles.net/puzzles/puzz_163.htm">Puzzle 163. P+SOD(P)</a>
%F A320879 A320879 = { n in A320878 | A062028(n) in A320878 } = { n = A320878(k) | A062028(n) = A320878(k+1) }.
%o A320879 (PARI) is_A320879(n)=isprime(n=A062028(n))&& is_A320878(n) \\ If possible, use this to select terms from a sufficiently large precomputed array A320878:
%o A320879 A320879 = select( is_A320879, A320878) \\ or, in that case, the more efficient:
%o A320879 A320879 = select( p->setsearch(A320878, A062028(p)), A320878) \\ or: vecextract(A320878, select(i->A062028(A320878[i])==A320878[i+1], [1..#A320878-1]))
%Y A320879 Cf. A047791, A048519, A062028 (n + digit sum of n).
%Y A320879 Cf. A048523 .. A048527.
%Y A320879 a(1) = A090009(8) = start of first chain of 8 primes under iteration of A062028.
%Y A320879 Subsequence of A320878; A320880 is a subsequence.
%K A320879 nonn,base
%O A320879 1,1
%A A320879 _Zak Seidov_ and _M. F. Hasler_, Nov 08 2018
%E A320879 a(16)-a(20) from _Lars Blomberg_, Feb 10 2019