A353387 a(n) is the least squared distance between 2 points of an n X n grid not occurring between two points of an (n-1) X (n-1) grid.

1, 4, 9, 16, 26, 36, 49, 64, 81, 101, 121, 144, 173, 196, 226, 256, 293, 324, 361, 401, 441, 484, 529, 576, 626, 677, 729, 784, 842, 904, 961, 1024, 1089, 1172, 1226, 1296, 1373, 1444, 1522, 1601, 1697, 1764, 1849, 1936, 2026, 2116, 2209, 2304, 2401, 2504, 2602, 2708

Offset

2,2

Links

Table of n, a(n) for n=2..53.

Prog

(PARI) a353387(nmax)={my(v=vectorsmall(2*nmax^2)); for(n=1, nmax, my(dfirst=0);
for(k=0, n, my(s=n^2+k^2); if(!v[s], if(!dfirst, print1(s, ", "); dfirst=1); v[s]++)))};
a353387(52)

Crossrefs

Cf. A001105, A001481, A047800.

First column of A353386.

Sequence in context: A143480 A230365 A274963 * A050461 A189835 A183764

Adjacent sequences: A353384 A353385 A353386 * A353388 A353389 A353390

Keyword

nonn

Author

Hugo Pfoertner, Apr 16 2022

Status

approved