OFFSET
1,2
LINKS
Eric Weisstein's World of Mathematics, Pronic Number
EXAMPLE
From Jesse Sealand, Oct 05 2019: (Start)
a(1) = 0 since A002378(0) = 0;
a(2) = 24 since A002378(24) = 600;
a(3) = 100 since A002378(100) = 10100;
a(4) = 624 since A002378(624) = 390000, etc.
(End).
MATHEMATICA
a[n_] := Block[{a = 0}, While[Count[IntegerDigits[a*(a + 1)], 0] != n, ++a]; Return[a]]; a /@ Range[1, 10] (* Julien Kluge, Dec 15 2016 *)
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
Patrick De Geest, May 15 1999
EXTENSIONS
a(16)-a(19) from Lars Blomberg, Jun 10 2011
Name edited by Jesse Sealand, Oct 05 2019
STATUS
approved