This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A328288 #20 Dec 23 2024 14:53:46
%S A328288 0,986409,0,438404,304,0,572175,153,157,0,219202,197,124,97,0,109601,
%T A328288 221,156,69,171,0,255752,73,88,142,68,69,0,140515,129,73,81,86,62,46,
%U A328288 0,109601,189,88,40,67,48,51,24,0,432645,89,80,77,31,63,68,41,20,0,0,0,132,80,90,58,32,63,99,37,0
%N A328288 Triangle T(m,n) = # { k | concat(mk,nk) has no digit twice or more }, m >= n >= 0.
%C A328288 This is an extended version of A328277 which is restricted to m > n >= 1.
%C A328288 One may consider T(m,n) defined for all m, n >= 0, which would yield a symmetric, infinite square array T(m,n), see formula.
%C A328288 For m and/or n = 0, see A328287(n) = T(0,n) = T(n,0), n >= 0.
%C A328288 The table is finite in the sense that T(m,n) = 0 for m > 987654321 (even if the multiple isn't pandigital, (mk, nk) cannot have more than 9+1 distinct digits), but also whenever the total number of digits of m and n exceeds 10.
%H A328288 M. F. Hasler, in reply to E. Angelini, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2019-October">Fractions with no repeated digits</a>, SeqFan list, Oct. 10, 2020.
%F A328288 T(m,n) = 0 whenever m == n (mod 10).
%F A328288 T(m,n) = T(n,m) for all m, n >= 0, if the condition m > n is dropped.
%e A328288 The table reads :
%e A328288 0, (m=0)
%e A328288 986409, 0, (m=1)
%e A328288 438404, 304, 0, (m=2)
%e A328288 572175, 153, 157, 0, (m=3)
%e A328288 219202, 197, 124, 97, 0, (m=4)
%e A328288 109601, 221, 156, 69, 171, 0, (m=5)
%e A328288 255752, 73, 88, 142, 68, 69, 0, (m=6)
%e A328288 140515, 129, 73, 81, 86, 62, 46, 0, (m=7)
%e A328288 109601, 189, 88, 40, 67, 48, 51, 24, 0, (m=8)
%e A328288 432645, 89, 80, 77, 31, 63, 68, 41, 20, 0, (m=9)
%e A328288 0, 0, 132, 80, 90, 58, 32, 63, 99, 37, 0, (m=10)
%e A328288 90212, 0, 106, 69, 79, 50, 30, 45, 30, 38, 0, 0, (m=11)
%e A328288 127163, 76, 0, 96, 31, 62, 54, 27, 31, 49, 41, 27, 0, (m=12)
%e A328288 75768, 84, 72, 0, 31, 58, 47, 26, 23, 34, 43, 25, 20, 0, (m=13)
%e A328288 62436, 100, 64, 52, 0, 51, 44, 51, 42, 22, 38, 27, 18, 20 0, (m=14)
%e A328288 ...
%e A328288 The terms corresponding to T(2,1) = 304 and T(3,1) = 153 are given in Eric Angelini's post to the SeqFan list.
%e A328288 Column 0 is A328287 (number of multiples of m that have only distinct and nonzero digits).
%o A328288 (PARI) T(m,n)=if(min(m,n), A328277(m,n), A328287(max(m,n)))
%K A328288 nonn,base,fini,tabl
%O A328288 0,2
%A A328288 _M. F. Hasler_, Oct 10 2019