OFFSET
1,2
EXAMPLE
a(1) * a(2) = 1 * 10 = 10;
a(2) * a(3) = 10 * 11 = 110;
a(3) * a(4) = 11 * 12 = 132;
a(4) * a(5) = 12 * 9 = 108;
a(5) * a(6) = 9 * 21 = 189; etc.
PROG
(Python)
def aupton(terms):
alst, aset = [1], {1}
while len(alst) < terms:
an, target = 2, str(alst[-1])[0]
while an in aset or target not in str(alst[-1]*an): an += 1
alst.append(an); aset.add(an)
return alst
print(aupton(200)) # Michael S. Branicky, Aug 21 2021
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, Aug 21 2021
STATUS
approved