A076671 -id:A076671 - cp's OEIS frontend

A076718 Duplicate of A076671.

5, 12, 16, 30, 40, 42, 56, 90, 120, 126, 168, 224, 360, 378, 504, 550, 1320, 1386, 1848

Offset: 1

dead

A076672 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=6.

6, 8, 15, 20, 21, 28, 45, 60, 63, 84, 112, 180, 189, 252, 275, 660, 693, 924, 1232, 1326, 1768, 1974, 2632, 4026, 5368, 6405, 8200, 8319, 11092, 11715, 15620, 16401, 19720, 20706, 20880, 20910, 24752, 24960, 25300, 26565, 29716

Offset: 1

Zak Seidov, Oct 25 2002

nonn

The sequence is infinite.

Cf. A076600, A076671 (starting at 5).

Clear[nxt]; nxt[n_]:=Module[{i=n+1},While[!IntegerQ[Sqrt[n^2+i^2]],i++]; i]; NestList[nxt,6,40] (* Harvey P. Dale, Dec 03 2010 *)

A076674 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=9.

Original entry on oeis.org

9, 12, 16, 30, 40, 42, 56, 90, 120, 126, 168, 224, 360, 378, 504, 550, 1320, 1386, 1848, 1989, 2652, 2961, 3948, 5264, 8052, 9711, 12948, 17264, 24852, 31311, 41748, 53289, 71052, 94736, 130548, 145061, 146280, 153594, 163392, 170280, 173290

Offset: 1

Zak Seidov, Oct 25 2002

nonn

The sequence is infinite.

Cf. A076600.

ps[n_]:=Module[{k=n+1,n2=n^2},While[!IntegerQ[Sqrt[n2+k^2]],k++];k]; NestList[ ps,9,40] (* Harvey P. Dale, May 01 2014 *)

a(n)=A076671(n), n>1. [From R. J. Mathar, Sep 20 2008]

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A076718 Duplicate of A076671.

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A076672 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=6.

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A076674 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=9.

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