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

0,2

Links

Table of n, a(n) for n=0..25.

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

Crossrefs

Cf. A099961, A099962, A099963.

Sequence in context: A326574 A280019 A063253 * A106531 A101163 A155587

Adjacent sequences: A099964 A099965 A099966 * A099968 A099969 A099970

Keyword

nonn,easy

Author

N. J. A. Sloane, Nov 13 2004

Extensions

More terms from Emeric Deutsch, Nov 16 2004

Status

approved