OFFSET
1,3
COMMENTS
Contains triples with base-7 digits 10^k1, 20^k2, 40^k4 for k >= 1, where ^ denotes repeated concatenation. - Michael S. Branicky, Aug 02 2022
LINKS
Patrick De Geest, World!Of Numbers, Palindromic cubes in bases 2 to 17.
PROG
(PARI) isok(k) = my(d=digits(k^3, 7)); Vecrev(d) == d; \\ Michel Marcus, Aug 02 2022
(Python)
from itertools import count, islice
from sympy.ntheory import is_palindromic as ispal
def agen(start=0): yield from (k for k in count(start) if ispal(k**3, 7))
print(list(islice(agen(), 22))) # Michael S. Branicky, Aug 02 2022
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, May 15 1998
EXTENSIONS
a(30)-a(36) from Michael S. Branicky, Aug 03 2022
STATUS
approved