login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A061583 a(1) = 1, a(n) is the number obtained by replacing each digit of a(n-1) with five times its value. 4
1, 5, 25, 1025, 501025, 250501025, 10250250501025, 501025010250250501025, 2505010250501025010250250501025, 1025025050102502505010250501025010250250501025 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Number of digits of each term is the sequence A038718. - Dmitry Kamenetsky, Jan 17 2009

LINKS

John Cerkan, Table of n, a(n) for n = 1..17

MAPLE

a:= proc(n) option remember; `if`(n=1, 1, (s-> parse(cat(

      seq(parse(s[i])*5, i=1..length(s)))))(""||(a(n-1))))

    end:

seq(a(n), n=1..10);  # Alois P. Heinz, May 25 2018

MATHEMATICA

NestList[FromDigits[Flatten[IntegerDigits/@(5*IntegerDigits[#])]]&, 1, 10] (* Harvey P. Dale, Dec 31 2013 *)

PROG

(Python)

def A061583_first(n):

    an = "1"

    a061583 = []

    while n > 1:

        a061583.append(int(an))

        newan = ""

        for i in an:

            newan += str(5*int(i))

        an = newan

        n -= 1

    a061583.append(int(an))

    return a061583 # John Cerkan, May 25 2018

CROSSREFS

Cf. A061581, A061582, A061584, A061585, A061586, A061587.

Sequence in context: A169652 A137114 A067212 * A278120 A039780 A328124

Adjacent sequences:  A061580 A061581 A061582 * A061584 A061585 A061586

KEYWORD

nonn,base,easy

AUTHOR

Amarnath Murthy, May 13 2001

EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org) and Asher Natan Auel (auela(AT)reed.edu), May 15 2001

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 14 15:36 EDT 2021. Contains 345025 sequences. (Running on oeis4.)