A008558 Repeatedly convert from decimal to octal.

9, 11, 13, 15, 17, 21, 25, 31, 37, 45, 55, 67, 103, 147, 223, 337, 521, 1011, 1763, 3343, 6417, 14421, 34125, 102515, 310163, 1135623, 4252007, 20160547, 114720043, 665476453, 4752456545, 43321135541, 502611010665, 7240574662151, 151272370273007

Offset: 1

Author

sbv(AT)VNET.IBM.COM (Scott Vetter), msvetter(AT)eng.xyplex.com (Mark Vetter)

Keywords

• nonn
• base

Crossrefs

Cf. A007094.

Programs

Mathematica

NestList[FromDigits[IntegerDigits[#,8]]&,9,40] (* Harvey P. Dale, Apr 09 2012 *)

Python

def aupton(terms):
    alst = [9]
    for n in range(2, terms+1): alst.append(int(oct(alst[-1])[2:]))
    return alst
print(aupton(35)) # Michael S. Branicky, Sep 11 2021