11,1

Also number of meaningful compositions of the k-th order of the differential operations and Gateaux directional derivative on the space R^10. - Branko Malesevic and Ivana Jovovic (ivana121(AT)EUnet.yu), Jun 20 2007

B. Malesevic: Some combinatorial aspects of differential operation composition on the space R^n, Univ. Beograd, Publ. Elektrotehn. Fak., Ser. Mat. 9 (1998), 29-33.

B. Malesevic, Some combinatorial aspects of differential operation composition on the space R^n

B. Malesevic and I. Jovovic, The Compositions of the Differential Operations and Gateaux Directional Derivative .

f(k+6)=f(k+5)+5*f(k+4)-4*f(k+3)-6*f(k+2)+3*f(k+1)+f(k)

NUM := proc(k :: integer) local i, j, n, Fun, Identity, v, A; n:=11; # <- DIMENSION Fun:=(i, j)->piecewise(((j=i+1) or (i+j=n+1)), 1, 0); Identity:=(i, j)->piecewise(i=j, 1, 0); v:=matrix(1, n, 1); A:=piecewise(k>1, (matrix(n, n, Fun))^(k-1), k=1, matrix(n, n, Identity)); return(evalm(v&*A&*transpose(v))[1, 1]); end:

Cf. A090989-A090995.

Cf. A000079, A007283, A020701, A020714.

Adjacent sequences: A129635 A129636 A129637 this_sequence A129639 A129640 A129641

Sequence in context: A109335 A086982 A064832 this_sequence A127624 A097616 A058489

nonn

Branko Malesevic (malesevic(AT)etf.bg.ac.yu), May 31 2007

More terms from Branko Malesevic and Ivana Jovovic (ivana121(AT)EUnet.yu), Jun 20 2007