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A183064
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Numbers k such that k^2+1 = 2*p^2, p prime.
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4
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7, 41, 8119, 47321, 63018038201, 2470433131948081, 96845919575610633161, 19175002942688032928599, 5834531641231893991002972081099601, 6733044458057842709277507685523012161, 228725309250740208744750893347264645481
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OFFSET
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1,1
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COMMENTS
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Subset of A002315 (Numbers k such that k^2 + 1 = 2*q^2).
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LINKS
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EXAMPLE
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a(2) = 41 because 41^2+1 = 2*29^2.
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MAPLE
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with(numtheory):for n from 1 to 1000000 do : p:=ithprime(n):x:=2*p^2: y:=sqrt(x-1):if
y=floor(y) then print(y):else fi:od:
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PROG
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(PARI) list(lim)=my(v=List(), w=3+quadgen(32), k, n); while((k=imag((1+w)*w^n++))<=lim, if(ispseudoprime(sqrtint((k^2+1)/2)), listput(v, k))); Vec(v) \\ Charles R Greathouse IV, Sep 14 2015
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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