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A076676 Smallest a(n)>a(n-1) such that a(n)^2+a(n-1)^2 is a perfect square, a(1)=11. 1
11, 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, 29835, 33048, 35055, 41496, 42997 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The sequence is infinite.

LINKS

Robert Israel, Table of n, a(n) for n = 1..986

MAPLE

A076600:= proc(n) local q;

  q:= max(select(t -> n^2/t - t > 2*n and (t - n^2/t)::even, numtheory:-divisors(n^2)));

  if q = -infinity then 0 else (n^2/q - q)/2 fi;

end proc:

A[1]:= 11;

for n from 2 to 100 do

  A[n]:= A076600(A[n-1]);

od:

seq(A[i], i=1..100); # Robert Israel, Mar 22 2018

CROSSREFS

Cf. A076600.

Sequence in context: A349120 A077036 A076604 * A044149 A044530 A050483

Adjacent sequences:  A076673 A076674 A076675 * A076677 A076678 A076679

KEYWORD

nonn

AUTHOR

Zak Seidov, Oct 25 2002

STATUS

approved

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Last modified May 23 03:15 EDT 2022. Contains 353959 sequences. (Running on oeis4.)