A035524 Reverse and add (in base 4).

1, 2, 4, 5, 10, 20, 25, 50, 85, 170, 340, 425, 850, 1385, 3070, 6140, 10225, 15335, 29410, 65135, 129070, 317675, 1280860, 2163725, 3999775, 7999550, 20321515, 81946460, 138412045, 255852575, 511705150, 1300234475, 5242880860

Offset

0,2

Links

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000

Index entries for sequences related to Reverse and Add!

Formula

a(n+1) = A055948(a(n)), a(0) = 1. [Reinhard Zumkeller, Oct 10 2011]

Mathematica

nxt4[n_]:=Module[{idn4=IntegerDigits[n, 4]}, FromDigits[idn4+ Reverse[idn4], 4]]; NestList[nxt4, 1, 40] (* Harvey P. Dale, May 02 2011 *)

Prog

(Haskell)
a035524 n = a035524_list !! n
a035524_list = iterate a055948 1
-- Reinhard Zumkeller, Oct 10 2011
(Python)
def reversedigits(n, b=10): # reverse digits of n in base b
    x, y = n, 0
    while x >= b:
        x, r = divmod(x, b)
        y = b*y + r
    return b*y + x
A035524_list, l = [1], 1
for _ in range(50):
    l += reversedigits(l, 4)
    A035524_list.append(l)

Crossrefs

Cf. A035522.

Cf. A030103.

Sequence in context: A128401 A394627 A018467 * A018283 A249398 A018489

Adjacent sequences: A035521 A035522 A035523 * A035525 A035526 A035527

Keyword

nonn,easy,nice,base

Author

N. J. A. Sloane

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Sep 22 2000

Status

approved