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A306689 Integers m with decimal expansion m = abc...z such that m is a multiple of both az and za; z may not be zero.

%I A306689 #27 Jun 19 2025 16:43:38
%S A306689 11,22,33,44,55,66,77,88,99,121,242,363,484,1001,1092,1111,1207,1221,
%T A306689 1275,1331,1441,1458,1512,1551,1661,1729,1771,1785,1881,1932,1991,
%U A306689 2002,2112,2184,2222,2332,2442,2552,2662,2772,2882,2992,3003,3276,3333,3663,3993,4004,4032
%N A306689 Integers m with decimal expansion m = abc...z such that m is a multiple of both az and za; z may not be zero.
%C A306689 Every power of 11 is a term. - _N. J. A. Sloane_, Jul 14 2019
%H A306689 Alois P. Heinz, <a href="/A306689/b306689.txt">Table of n, a(n) for n = 1..10000</a>
%e A306689 1512 is in the list since 12*126=1512 and 21*72=1512.
%o A306689 (Python)
%o A306689 for a in range(1,1000):
%o A306689    for b in range (1, 10):
%o A306689       numb = 10*a + b
%o A306689       f = int(str(numb)[0])
%o A306689       first = 10*f + b
%o A306689       last = 10*b + f
%o A306689       if numb %  first == 0 and numb % last == 0 :
%o A306689          print(numb, end=', ')
%Y A306689 Cf. A073729.
%K A306689 nonn,base
%O A306689 1,1
%A A306689 _Reiner Moewald_, Mar 05 2019