A098736 - OEIS

%I #22 Aug 06 2020 01:05:10

%S 0,1,4,9,16,25,36,49,64,81,0,11,24,39,56,75,96,119,144,171,0,42,88,

%T 138,192,250,312,378,448,522,0,93,192,297,408,525,648,777,912,1053,0,

%U 164,336,516,704,900,1104,1316,1536,1764,0,255,520,795,1080,1375,1680,1995

%N a(n) = product of n and all its digits.

%H Vincenzo Librandi, <a href="/A098736/b098736.txt">Table of n, a(n) for n = 0..1000</a>

%H <a href="/index/Coi#Colombian">Index entries for Colombian or self numbers and related sequences</a>

%F If n=abcd (say) in decimal, then a(n) = abcd * a * b * c * d.

%F a(n) = n*A007954(n). - _R. J. Mathar_, Sep 27 2013

%e a(15) = 15*1*5=75

%p with transforms; [seq(n*digprod(n), n=0..200)]; # _N. J. A. Sloane_, Oct 12 2013

%t Array[# Times@@ IntegerDigits@#&, 60, 0] (* _Vincenzo Librandi_, Oct 13 2013 *)

%o (PARI) a(n) = vecprod(digits(n))*n; \\ _Michel Marcus_, Aug 06 2020

%Y Cf. A007954, A230101.

%K base,easy,nonn

%O 0,3

%A _Alexandre Wajnberg_, Sep 30 2004

%E More terms from _Sam Alexander_, Jan 06 2005

%E Corrected by _Vincenzo Librandi_, Oct 13 2013