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 A108415 a(n) = 1, 2 or 3 (resp.) if prime(n) is weak, balanced or strong (resp.). 1
 1, 2, 1, 3, 1, 3, 1, 1, 3, 1, 3, 3, 1, 1, 2, 3, 1, 3, 3, 1, 3, 1, 1, 3, 3, 1, 3, 1, 1, 3, 1, 3, 1, 3, 1, 2, 3, 1, 2, 3, 1, 3, 1, 3, 1, 2, 3, 3, 1, 1, 3, 1, 3, 2, 2, 3, 1, 3, 3, 1, 1, 3, 3, 1, 1, 3, 1, 3, 1, 1, 1, 3, 2, 3, 1, 1, 3, 1, 1, 3, 1, 3, 1, 3, 1, 1, 3, 3, 1, 1, 3, 3, 1, 3, 1, 1, 3, 1, 3, 1, 3, 2, 3, 1, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,2 COMMENTS n >= 2: a(n) = 1, 2 or 3 (resp.) if n-th prime is in A051635, A006562 or A051634 (resp.). LINKS Robert Israel, Table of n, a(n) for n = 2..10000 Wikipedia, Balanced prime MAPLE p:= 2: q:= 3: r:= 5: for i from 2 to 200 do   t:= q - (p+r)/2;   A[i]:= piecewise(t<0, 1, t=0, 2, 3);   p:= q; q:= r; r:= nextprime(r); od: seq(A[i], i=2..200); # Robert Israel, Mar 25 2018 MATHEMATICA A108415[n_]:=2+Sign[Prime[n]-1/2(Prime[n-1]+Prime[n+1])] CROSSREFS Cf. A006562, A051634, A051635. Sequence in context: A287561 A046924 A015710 * A278572 A136644 A111963 Adjacent sequences:  A108412 A108413 A108414 * A108416 A108417 A108418 KEYWORD nonn AUTHOR Zak Seidov, Jun 02 2005 STATUS approved

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Last modified October 1 04:06 EDT 2020. Contains 337441 sequences. (Running on oeis4.)