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A260179 Primes pr(k) such that pr(k)+pr(k+1)+pr(k+6)+pr(k+7) = pr(k+2)+pr(k+3)+pr(k+4)+pr(k+5). 3

%I #19 May 06 2020 01:47:22

%S 17,23,71,149,173,233,331,359,389,419,431,503,677,727,839,853,937,971,

%T 1019,1201,1229,1277,1327,2213,2221,2237,2593,2689,2797,2999,3019,

%U 3167,3221,3253,3821,3823,4027,4111,4201,4219,4231,4801,5147,5309,5407,5437

%N Primes pr(k) such that pr(k)+pr(k+1)+pr(k+6)+pr(k+7) = pr(k+2)+pr(k+3)+pr(k+4)+pr(k+5).

%H Amiram Eldar, <a href="/A260179/b260179.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..500 from R. J. Mathar)

%e Starting from 71, the eight consecutive primes are 71, 73, 79, 83, 89, 97, 101, 103; and they satisfy 71+73+101+103=79+83+89+97, so 71 is in the sequence.

%p n := 1 ;

%p Lp := [[0,1,6,7],[2,3,4,5]] ;

%p for i from 1 do

%p if add(ithprime(i+j),j=op(1,Lp)) = add(ithprime(i+j),j=op(2,Lp)) then

%p printf("%d %d\n",n,ithprime(i)) ;

%p n := n+1 ;

%p end if;

%p end do: # _R. J. Mathar_, Aug 06 2015

%t pr8Q[lst_]:=With[{tadr=TakeDrop[lst,{3,6}]},Total[tadr[[1]]] == Total[ tadr[[2]]]]; Transpose[Select[Partition[Prime[ Range[ 1000]],8,1], pr8Q]][[1]] (* The program uses the TakeDrop function from Mathematica version 10.2 *)

%Y Cf. A022885.

%K nonn

%O 1,1

%A _Harvey P. Dale_, Jul 17 2015

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Last modified August 2 10:23 EDT 2024. Contains 374838 sequences. (Running on oeis4.)