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A048535 a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 3's.

%I A048535 #36 Feb 16 2025 08:32:40
%S A048535 5,36,182,1817,4830,5773,153079,577355,3659694,18366636,182574188,
%T A048535 576484036,1839384036,17701331569,36542213005,485935528988,
%U A048535 1814754484036,5755287250288,5773506159694,182738579159694,230940107675430,1820173984357898,18202838331788627,57475066797119386,182305878493709942
%N A048535 a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 3's.
%H A048535 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PronicNumber.html">Pronic Number</a>
%e A048535 From _Jesse Sealand_, Oct 05 2019: (Start)
%e A048535 a(1) = 5 since A002378(5) = 30;
%e A048535 a(2) = 36 since A002378(36) = 1332;
%e A048535 a(3) = 182 since A002378(182) = 33306;
%e A048535 a(4) = 1817 since A002378(1817) = 3303306, etc.
%e A048535 (End)
%t A048535 With[{s = 2 Accumulate[Range[0, 10^6]]}, Table[-1 + FirstPosition[s, _?(DigitCount[#, 10, 3] == n &)][[1]], {n, 8}]] (* _Michael De Vlieger_, Oct 05 2019 *)
%Y A048535 Cf. A048536, A002378 (oblong numbers).
%Y A048535 Cf. A048529, A048531, A048533, A048537, A048539, A048541, A048543, A048545, A048547.
%K A048535 nonn,base
%O A048535 1,1
%A A048535 _Patrick De Geest_, May 15 1999
%E A048535 a(13)-a(16) from _Lars Blomberg_, Jun 10 2011
%E A048535 Name edited by _Jesse Sealand_, Oct 05 2019
%E A048535 a(17) from _Giovanni Resta_, Oct 09 2019
%E A048535 a(18)-a(25) from _Max Alekseyev_, Jul 25 2024