A102251 - OEIS

A102251

Begin with 1, multiply each digit by 2.

1, 2, 4, 8, 16, 2, 12, 4, 2, 4, 8, 4, 8, 16, 8, 16, 2, 12, 16, 2, 12, 4, 2, 4, 2, 12, 4, 2, 4, 8, 4, 8, 4, 2, 4, 8, 4, 8, 16, 8, 16, 8, 4, 8, 16, 8, 16, 2, 12, 16, 2, 12, 16, 8, 16, 2, 12, 16, 2, 12, 4, 2, 4, 2, 12, 4, 2, 4, 2, 12, 16, 2, 12, 4, 2, 4, 2, 12, 4, 2, 4, 8, 4, 8, 4, 2, 4, 8, 4, 8, 4, 2, 4

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

COMMENTS

Same digits as A061581 without the memory of the groupings of the preceding digits. A bunch of sequences can be produced with this rule: a(n)=d*k beginning with 1,2,3... for k=2,3,...

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

FORMULA

d*2, beginning with 1

EXAMPLE

Read a(5)=16 which produces a(6)=2 because 1*2=2 and a(7)=12 because 6*2=12. Now read a(6)=2 which produces [a(7) is already written] a(8)=4 because 2*2=4.

MATHEMATICA

Flatten[ NestList[ Function[x, Flatten[ FromDigits /@ 2IntegerDigits[ x]]], 1, 15]] (* Robert G. Wilson v, Feb 21 2005 *)

PROG

(Haskell)

a102251 n = a102251_list !! n

a102251_list = 1 : (map (* 2) $

concatMap (map (read . return) . show) a102251_list)

-- Reinhard Zumkeller, Oct 02 2014

CROSSREFS

Cf. A061581.

Cf. A248131.

Sequence in context: A110333 A247292 A069783 * A339853 A373944 A218338