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A155932 Integers a(n) such that cube(n)-square(x) and cube(n)+square(x) are primes. 0
3, 6, 7, 8, 10, 13, 15, 18, 20, 21, 22, 28, 33, 35, 37, 39, 42, 43, 45, 48, 52, 57, 58, 60, 62, 63, 68, 72, 73, 75, 77, 78, 80, 82, 83, 85, 86, 87, 90, 91, 92, 93, 95, 97, 99, 102, 103, 105, 106, 107, 108, 111, 112, 113, 115, 117, 120, 123, 125, 128, 129, 132, 133, 135 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

3^3-2^2=23;3^3+2^2=31, 6^3-5^2=191;6^3+5^2=241, 7^3-6^2=307;7^3+6^2=379, ...

LINKS

Table of n, a(n) for n=1..64.

MATHEMATICA

lst={}; Do[k=n; c=n^3; Label[ax]; s=k^2; p1=c-s; p2=c+s; If[PrimeQ[p1]&&PrimeQ[p2], AppendTo[lst, n], k--; If[k>0, Goto[ax]]], {n, 2*5!}]; lst

CROSSREFS

Cf. A155929, A155930, A155931

Sequence in context: A295566 A266986 A047283 * A298980 A206586 A289176

Adjacent sequences:  A155929 A155930 A155931 * A155933 A155934 A155935

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Jan 30 2009

STATUS

approved

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Last modified August 22 20:47 EDT 2019. Contains 326209 sequences. (Running on oeis4.)