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A085400 a(n) = abs(A085061(n-1) - A085061(n)). 2

%I

%S 2,3,13,5,7,17,19,11,23,29,31,41,37,43,47,53,59,61,67,71,83,73,79,89,

%T 97,101,103,107,109,113,127,131,137,139,149,157,151,163,167,173,179,

%U 181,191,193,197,199,211,223,227,229,233,239,241,251,257,263,269,271,277

%N a(n) = abs(A085061(n-1) - A085061(n)).

%C Primes used in constructing the terms of A085061. Except for an initial part of the sequence and occasional transpositions later on (e.g. 157,151; 691,683) the primes appear in ascending order.

%e a(8) = abs(A085061(7) - A085061(8)) = abs(23 - 34) = 11.

%o (PARI) {in(n,v)=local(j,s,b); j=1; s=matsize(v)[2]; b=1; while(b&&j<=s,if(n==v[j],b=0,j++)); !b}

%o {a=1; v=[]; for(n=1,60,p=2; t=1; while(t>0,if(in(p,v),p=nextprime(p+1),if(!isprime(2*a+p),t=0; b=a+p,if(p<a&&!isprime(2*a-p),t=0; b=a-p,p=nextprime(p+1))))); v=concat(v,p); print1(p,","); a=b)}

%Y Cf. A085061, A085402.

%K nonn

%O 1,1

%A _Klaus Brockhaus_, Jun 28 2003

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Last modified April 17 02:26 EDT 2021. Contains 343059 sequences. (Running on oeis4.)