0,2

(PARI) {a(n)=local(M=matrix(n+1, n+1)); for(r=1, n+1, for(c=1, r, M[r, c]=if(r==c, 1, if(c>1, (M^4)[r-1, c-1])+(M^4)[r-1, c]))); return(if(n<1, 0, (M^4)[n+1, 2]))}

Cf. A113101.

Adjacent sequences: A113099 A113100 A113101 this_sequence A113103 A113104 A113105

Sequence in context: A041760 A117798 A006424 this_sequence A066802 A066798 A072035

nonn

Paul D. Hanna (pauldhanna(AT)juno.com), Oct 14 2005