A048533 - OEIS

%I #23 Jul 25 2024 11:05:53

%S 1,16,141,458,1458,10593,36458,471933,471404,3496458,14930593,

%T 149072541,471446966,149071198,14907133333,114989226548,471404524016,

%U 1510636363333,14360440530228,47140441472504,149071332733333,1490343155861166,4712983368549333,24955404665166666,149070527690846966

%N a(n) is the smallest value of m such that A002378(m), the m-th oblong number, contains exactly n 2's.

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PronicNumber.html">Pronic Number</a>

%e From _Jesse Sealand_, Oct 06 2019: (Start)

%e a(1) = 1 since A002378(1) = 2;

%e a(2) = 16 since A002378(16) = 272;

%e a(3) = 141 since A002378(141) = 20022;

%e a(4) = 458 since A002378(458) = 210222, etc.

%e (End).

%Y Cf. A048534, A002378.

%Y Cf. A048529, A048531, A048535, A048537, A048539, A048541, A048543, A048545, A048547.

%K nonn,base

%O 1,2

%A _Patrick De Geest_, May 15 1999

%E a(15)-a(16) from _Lars Blomberg_, Jun 10 2011

%E Name edited by _Jesse Sealand_, Oct 06 2019

%E a(17) from _Giovanni Resta_, Oct 09 2019

%E a(18)-a(25) from _Max Alekseyev_, Jul 25 2024