|
Search: id:A026299
|
|
|
| A026299 |
|
Number of (s(0), s(1), ..., s(n)) such that every s(i) is a nonnegative integer, s(0) = 0, s(1) = 1, |s(i) - s(i-1)| <= 1 for i >= 2, |s(2) - s(1)| = 1, |s(3) - s(2)| = 1 if s(2) = 1. Also sum of numbers in row n+1 of the array T in A026268. |
|
+0
1
|
|
| 1, 3, 7, 19, 53, 149, 422, 1202, 3440, 9884, 28495, 82387, 238801, 693689, 2018981, 5886329, 17187891, 50257299, 147135189, 431245977, 1265264799, 3715761759, 10921722348, 32127865392, 94578844458, 278614855862, 821281118993, 2422356077357, 7148679142639
(list; graph; listen)
|
|
|
OFFSET
|
0,2
|
|
|
MAPLE
|
A026268 := proc(nmax) local T, i, j; T := array(0..nmax, 0..nmax) ; for i from 0 to nmax do T[i, 0] := 1; od ; T[1, 1] := 1 ; if nmax >= 2 then T[2, 1] := 1 ; T[2, 2] := 1 ; fi ; if nmax >= 3 then T[3, 1] := 2 ; T[3, 2] := 2 ; T[3, 3] := 2 ; fi ; for i from 4 to nmax do T[i, 1] := i-1 ; T[i, i] := T[i-1, i-2]+T[i-1, i-1] ; for j from 2 to i-1 do T[i, j] := T[i-1, j-2]+T[i-1, j-1]+T[i-1, j] ; od ; od ; RETURN(T) ; end: A026299 := proc(n) local T ; if n =0 then RETURN(1) ; else T := A026268(n+1) ; sum(T[n+1, i], i=0..n+1) ; fi ; end ; for n from 0 to 30 do printf("%d, ", A026299(n)) ; od ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 31 2006
|
|
CROSSREFS
|
Adjacent sequences: A026296 A026297 A026298 this_sequence A026300 A026301 A026302
Sequence in context: A007180 A059506 A007575 this_sequence A078481 A104522 A115760
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Clark Kimberling (ck6(AT)evansville.edu)
|
|
EXTENSIONS
|
Corrected and extended by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 31 2006
|
|
|
Search completed in 0.002 seconds
|
