OFFSET
1,1
COMMENTS
Conjecture: for n > 26069, a(n) = n + 3715. [Charles R Greathouse IV, Sep 28 2011]
REFERENCES
C. Pickover, Mazes for the Mind, St. Martin's Press, NY, 1992, p. 337.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
Brady Haran and Tony Padilla, Apocalyptic Numbers, YouTube Numberphile video, 2024.
Eric Weisstein's World of Mathematics, Apocalyptic Number.
EXAMPLE
a(1) = 157 is a term since 2^a(1) = 2^157 = 182687704666362864775460604089535377456991567872 contains 666.
MAPLE
q:= n-> searchtext("666", cat(2^n))>0:
select(q, [$1..1000])[]; # Alois P. Heinz, Oct 26 2019
MATHEMATICA
Select[Range[650], SequenceCount[IntegerDigits[2^#], {6, 6, 6}]>0&] (* Harvey P. Dale, Apr 10 2022 *)
PROG
(Python)
A007356_list = [k for k in range(1000) if '666' in str(2**k)] # Chai Wah Wu, Oct 26 2019
CROSSREFS
KEYWORD
base,nonn
AUTHOR
STATUS
approved