A099967 Second column of triangle in A099961.

1, 2, 3, 5, 10, 23, 51, 128, 386, 1092, 3370, 12458, 43037, 158638, 691999, 2827035, 12150430, 60980759, 287737037, 1414689552, 8021603122, 42939104470, 237864297110, 1502870474645, 8999347646633, 55484973357830

Offset: 0

Author

N. J. A. Sloane, Nov 13 2004

Keywords

• nonn
• easy

Crossrefs

Cf. A099961, A099962, A099963.

Programs

Maple

with(linalg):rev:=proc(a) local n, p; n:=vectdim(a): p:=i->a[n+1-i]: vector(n,p) end: ps:=proc(a) local n, q; n:=vectdim(a): q:=i->sum(a[j],j=1..i): vector(n,q) end: pss:=proc(a) local n, q; n:=vectdim(a): q:=proc(i) if i<=n then sum(a[j],j=1..i) else sum(a[j],j=1..n) fi end: vector(n+1,q) end: R[0]:=vector(1,1): for n from 1 to 31 do if n mod 3 = 0 or n mod 3 = 1 then R[n]:=ps(rev(R[n-1])) else R[n]:=pss(rev(R[n-1])) fi od: seq(R[n][2],n=2..31); # Emeric Deutsch, Nov 16 2004

Extensions

More terms from Emeric Deutsch, Nov 16 2004