A113152 - OEIS

A113152

a(1) = 2; a(n) is the smallest prime > a(n-1) such that a(n) + a(n-1) is a fourth power.

2, 79, 1217, 2879, 7121, 152879, 178897, 12781103, 24233953, 25553183, 29147633, 70852367, 1800921329, 3205490207, 6270364129, 30533756207, 39265770209, 52240479791, 68933130209, 73192853807, 74570506193, 78996293183

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OFFSET

1,1

COMMENTS

Cf. similar sequences A062064, A062066.

LINKS

Table of n, a(n) for n=1..22.

EXAMPLE

2+79=3^4, 79+1217=6^4, etc.

MATHEMATICA

a=2; s={a}; Do[p=n^4-a; If[p>a&&PrimeQ[p], AppendTo[s, p]; a=p], {n, 2, 3000}]; s

sp4p[n_]:=Module[{k=NextPrime[n]}, While[!IntegerQ[Surd[n+k, 4]], k = NextPrime[ k]]; k]; NestList[sp4p, 2, 21] (* Harvey P. Dale, Apr 02 2018 *)

PROG

(PARI) print1(s=a=2); for(n=1, 99, until(isprime(s++^4-a), ); print1(", "a=s^4-a)) \\ M. F. Hasler, Oct 03 2010

CROSSREFS

Cf. A062064, A062066.

Sequence in context: A342979 A166052 A045484 * A265585 A060051 A100421

Adjacent sequences: A113149 A113150 A113151 * A113153 A113154 A113155

KEYWORD

nonn

AUTHOR

Zak Seidov, Jan 04 2006

EXTENSIONS

Edited by Zak Seidov, Sep 28 2010, Oct 03 2010

STATUS

approved