OFFSET
1,2
FORMULA
Conjecture: a(2*n+1) = n^3, a(2*n) = 7*n^3 - 9*n^2 + 5*n - 1.
Conjecture: a(n) = 4*a(n-2)-6*a(n-4)+4*a(n-6)-a(n-8) for n>8. - Colin Barker, Nov 05 2014
Empirical g.f.: x^2*(x^6+x^5+18*x^4+4*x^3+21*x^2+x+2) / ((x-1)^4*(x+1)^4). - Colin Barker, Nov 05 2014
Empirical first differences of A212763.
PROG
(PARI) v=[]; n=0; while(n<50000, num=(vecsum(v)+n); if(num%(#v+1)==0&&vecsearch(vecsort(v), n)==0, for(i=0, n, if(i^3>(num/(#v+1)), break); if(i^3==(num/(#v+1)), print1(n, ", "); v=concat(v, n); n=0; break))); n++)
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Nov 05 2014
STATUS
approved