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 A181103 a(n) is the least prime greater than a(n-1) such that abs(a(n-2) + a(n-1) - a(n)) is prime; a(1)=2, a(2)=3. 4
 2, 3, 7, 13, 17, 19, 23, 29, 41, 47, 59, 83, 89, 101, 107, 137, 173, 179, 239, 251, 257, 269, 293, 311, 347, 389, 419, 449, 467, 557, 563, 599, 641, 647, 701, 761, 809, 827, 839, 857, 887, 947, 953, 971, 977, 1019, 1049, 1091, 1109, 1151, 1163, 1217, 1229 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Partial products are in A181737. LINKS Nathaniel Johnston, Table of n, a(n) for n = 1..10000 MAPLE A181103 := proc(n) option remember: local p: if(n<=2)then return n+1: fi: p:=procname(n-1): do p:=nextprime(p): if(isprime(abs(p-procname(n-2)-procname(n-1))))then return p: fi: od: end: seq(A181103(n), n=1..53); # Nathaniel Johnston, May 27 2011 MATHEMATICA nxt[{a_, b_}]:=Module[{lp=NextPrime[b]}, While[!PrimeQ[Abs[a+b-lp]], lp= NextPrime[ lp]]; {b, lp}]; Transpose[NestList[nxt, {2, 3}, 60]][[1]] (* Harvey P. Dale, Feb 08 2015 *) PROG (MAGMA) A181103:=function(n); S:=[2, 3]; if n le 2 then return S[n]; end if; p:=5; for k in [3..n] do while not IsPrime(Abs(S[k-2]+S[k-1]-p)) do p:=NextPrime(p); end while; Append(~S, p); if k eq n then return p; end if; p:=NextPrime(p); end for; end function; [ A181103(n): n in [1..55] ]; // Klaus Brockhaus, Dec 19 2010 CROSSREFS Cf. A181737. Sequence in context: A101739 A141633 A045327 * A329487 A220814 A045328 Adjacent sequences:  A181100 A181101 A181102 * A181104 A181105 A181106 KEYWORD nonn,easy AUTHOR Giovanni Teofilatto, Oct 03 2010 EXTENSIONS Definition refined and sequence extended by R. J. Mathar, Oct 12 2010 Index in definition corrected by R. J. Mathar, Oct 26 2010 STATUS approved

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Last modified May 28 21:37 EDT 2020. Contains 334690 sequences. (Running on oeis4.)