OFFSET
1,3
COMMENTS
Includes all squares not in A052041. - Robert Israel, May 25 2020
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
26569 is in the sequence because (1) it is a square, (2) the product of its digits is 2*6*5*6*9=3240 which is a triangular number.
MAPLE
filter:= n -> issqr(1+8*convert(convert(n, base, 10), `*`)):
select(filter, [seq(i^2, i=1..1000)]); # Robert Israel, May 25 2020
MATHEMATICA
Select[Range[0, 120]^2, OddQ[Sqrt[8 (Times@@IntegerDigits[#]) +1]]&] (* Harvey P. Dale, Jul 06 2021 *)
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), May 05 2006
EXTENSIONS
1600 inserted by Robert Israel, May 25 2020
STATUS
approved