A026495 a(n) = least positive integer > a(n-1) and not a(i)^2 + a(j)^2 + a(k)^2 for 1<=i<j<k<=n.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 27, 28, 31, 32, 33, 34, 36, 37, 39, 40, 43, 44, 47, 48, 51, 52, 55, 57, 58, 60, 63, 64, 67, 68, 71, 72, 73, 76, 79, 80, 82, 85, 87, 88, 92, 95, 96, 97, 99, 100, 102, 103, 108, 111, 112, 119, 123

Offset

1,2

Links

Klaus Brockhaus, Table of n, a(n) for n=1..10000

Prog

(PARI) {m=70; z=300; a=[]; a2=Set([]); a3=Set([]); s=1; for(n=1, m, p=s; while(setsearch(a3, p, 0), p++); if(p>z, break); new=vector(#a2); for(k=1, #a2, q=eval(a2[k])+p^2; if(q<=z, new[k]=q)); a3=setunion(a3, Set(new)); new=vector(#a); for(k=1, #a, q=a[k]^2+p^2; if(q<=z, new[k]=q)); a2=setunion(a2, setminus(Set(new), Set(0))); a=concat(a, p); s=p+1; print1(p, ", "))} /* Klaus Brockhaus, Jul 03 2008 */

Crossrefs

Cf. A004440. [From R. J. Mathar, Oct 23 2008]

Sequence in context: A056651 A022772 A004440 * A004437 A298534 A291442

Adjacent sequences: A026492 A026493 A026494 * A026496 A026497 A026498

Keyword

nonn

Author

Clark Kimberling

Extensions

Extended by Klaus Brockhaus, Jul 03 2008

Status

approved