OFFSET
1,1
LINKS
Chai Wah Wu, Table of n, a(n) for n = 1..10000
MATHEMATICA
fQ[n_] := Block[{c = DigitCount@ n}, And[Plus @@ Take[c, {5, 9}] == 0, c[[4]] > 0, c[[10]] > 0]]; Select[Range@ 10000000, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 12 2015 *)
PROG
(PARI) is(n) = vecmin(digits(n))==0 && vecmin(digits(n^2))==0 && vecmax(digits(n))==4 && vecmax(digits(n^2))==4
(Python)
from itertools import product
A256630_list = []
for l in range(11):
for a in ('1', '2', '3', '4'):
for b in product('01234', repeat = l):
for c in ('0', '1', '2'):
s = a+''.join(b)+c
if '0' in s and '4' in s:
n = int(s)
s2 = set(str(n**2))
if {'0', '4'} <= s2 <= {'0', '1', '2', '3', '4'}:
A256630_list.append(n)
print(A256630_list) # Chai Wah Wu, Apr 17 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Felix Fröhlich, Apr 05 2015
EXTENSIONS
More terms from Alois P. Heinz, Apr 16 2015
STATUS
approved