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!)
A061585 a(1) = 1, a(n)= number obtained by replacing each digit of a(n-1) with seven times its value. 3
1, 7, 49, 2863, 14564221, 72835422814147, 49145621352814145672872849, 286372835421472135145672872835424914564914562863, 1456422149145621352814728491472135728354249145649145621352814286372835422863728354214564221 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

John Cerkan, Table of n, a(n) for n = 1..12

MATHEMATICA

NestList[FromDigits[Flatten[IntegerDigits/@(7*IntegerDigits[#])]]&, 1, 10] (* Harvey P. Dale, Jan 23 2015 *)

PROG

(PARI) A061585(n=2, a=1, m=7)={while(n--, a=eval(concat(apply(t->Str(t), digits(a)*m)))); a} \\ If only the 2nd argument is given, then the operation is applied once to that argument. - M. F. Hasler, Jun 24 2016

(Python)

def A061585_first(n):

    an = "1"

    a061585 = []

    while n > 1:

        a061585.append(int(an))

        newan = ""

        for i in an:

            newan += str(7*int(i))

        an = newan

        n -= 1

    a061585.append(int(an))

    return a061585 # John Cerkan, May 25 2018

CROSSREFS

Cf. A061581, A061582, A061583, A061584, A061586, A061587.

Sequence in context: A229041 A263247 A259990 * A202782 A067214 A069032

Adjacent sequences:  A061582 A061583 A061584 * A061586 A061587 A061588

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

Corrected by Harvey P. Dale, Jan 23 2015

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 July 25 09:49 EDT 2021. Contains 346289 sequences. (Running on oeis4.)