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a(n) = product of first n digits in the decimal expansion of Pi, ignoring decimal point.
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%I #18 Sep 27 2014 14:27:10

%S 1,3,3,12,12,60,540,1080,6480,32400,97200,486000,3888000,34992000,

%T 244944000,2204496000,6613488000,13226976000,39680928000,317447424000,

%U 1269789696000,7618738176000,15237476352000,91424858112000,365699432448000,1097098297344000

%N a(n) = product of first n digits in the decimal expansion of Pi, ignoring decimal point.

%C The 33rd digit of Pi is 0, so a(33), a(34), .... = 0. - Philip Bergonio (percyweasley99(AT)yahoo.com), Feb 24 2003

%H Alois P. Heinz, <a href="/A073055/b073055.txt">Table of n, a(n) for n = 0..100</a>

%e Pi = 3.141592653589793... so a(0) = 1, a(1) = 3, a(2) = 3*1=3, a(3) = 3*1*4=12, a(4) = 3*1*4*1 = 12 and so on.

%t FoldList[Times, 1, First[RealDigits[N[Pi, 50]]]] (Cunningham)

%Y Cf. A000796.

%K easy,nonn,base

%O 0,2

%A Y. Kelly Itakura (yitkr(AT)mta.ca), Aug 22 2002

%E Corrected and extended by Gabriel Cunningham (gcasey(AT)mit.edu), Oct 25 2004