A061586 a(1) = 1, a(n)= number obtained by replacing each digit of a(n-1) with eight times its value.

1, 8, 64, 4832, 32642416, 241648321632848, 1632848326424168482416643264, 84824166432642416483216328486432641632848483224164832, 64326416328484832241648321632848326424168482416643264483224164832848241664326432642416163284832642416

Offset: 1

Author

Amarnath Murthy, May 13 2001

Keywords

• nonn
• base
• easy

Links

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

Crossrefs

Cf. A061581-A061587.

Programs

Mathematica

NestList[FromDigits[Flatten[IntegerDigits/@(8*IntegerDigits[#])]]&,1,10] (* Harvey P. Dale, Sep 22 2012 *)

Python

def A061586_first(n):
    an = "1"
    cnt = 1
    a061586 = []
    while cnt < n:
        a061586.append(int(an))
        newan = ""
        for i in an:
            newan += str(8*int(i))
        an = newan
        cnt += 1
    a061586.append(int(an))
    return a061586 # John Cerkan, May 25 2018

Extensions

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