A075373 a(1)=0, a(2)=9; then distinct squares such that the sum of three successive terms is a square.

0, 9, 16, 144, 36, 1936, 242064, 11025, 360000, 19600, 1089, 106998336, 1806336, 9048064, 9216, 239121, 23104, 2250000, 3240000, 9025, 2985984, 1332542016, 301401, 2102405904, 102252544, 1289097216, 19554084, 7441984, 1115136, 4356

Offset

1,2

Links

Andrew Howroyd, Table of n, a(n) for n = 1..10000 (terms 1..153 from Sean A. Irvine)

Prog

(PARI) lista(n)={my(v=vector(n), M=Map()); v[2]=9; mapput(M, 3, 1); for(i=3, n, my(s=v[i-1]+v[i-2]); fordiv(s, d, my(t=(d-s/d)/2); if(t>0&&!frac(t)&&!mapisdefined(M, t), mapput(M, t, 1); v[i]=t^2; break)); if(!v[i], v=v[1..i-1]; break)); v} \\ Andrew Howroyd, Feb 17 2025

Crossrefs

Sequence in context: A226232 A267088 A204268 * A072470 A053911 A171522

Adjacent sequences: A075370 A075371 A075372 * A075374 A075375 A075376

Keyword

nonn

Author

Amarnath Murthy, Sep 20 2002

Extensions

More terms from David Wasserman, Jan 16 2005

Status

approved