OFFSET
0,5
COMMENTS
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
MAPLE
R:= n-> (s-> parse(cat(s[-i]$i=1..length(s))))(""||n):
a:= proc(n) option remember; `if`(n<3, binomial(n, 2),
R(R(a(n-1)) + R(a(n-2)) + R(a(n-3))))
end:
seq(a(n), n=0..50); # Alois P. Heinz, Jun 18 2014
MATHEMATICA
R[n_]:=FromDigits[Reverse[IntegerDigits[n]]]; Clear[a]; a[0]=0; a[1]=0; a[2]=1; a [n_]:=a[n]=R[R[a[n-1]]+R[a[n-2]]+R[a[n-3]]]; Table[a[n], {n, 0, 40}]
rev[n_]:=FromDigits[Reverse[IntegerDigits[n]]]; nxt[{a_, b_, c_}] := {b, c, rev[rev[a] + rev[b] + rev[c]]}; Transpose[NestList[nxt, {0, 0, 1}, 40]][[1]] (* Harvey P. Dale, Mar 20 2015 *)
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Jonathan Vos Post and Ray Chandler, Dec 30 2004
STATUS
approved