OFFSET
0,3
EXAMPLE
136 is in the sequence because (1) it is a triangular number and (2) the product of its digits 1*3*6=18 is a heptagonal number.
PROG
(PARI) isok(k) = ispolygonal(k, 3) && ispolygonal(vecprod(digits(k)), 7); \\ Michel Marcus, Mar 27 2024
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Luc Stevens (lms022(AT)yahoo.com), Apr 26 2006
EXTENSIONS
a(24) and a(38) corrected by Georg Fischer, Mar 27 2024
STATUS
approved