A343645 - OEIS

%I #13 Apr 24 2021 08:51:39

%S 1,1,1,1,1,1,1,1,1,2,12,10,12,14,16,18,20,22,24,6,52,30,21,24,27,30,

%T 33,36,39,12,70,84,56,36,40,44,48,52,56,20,90,105,120,90,55,60,65,70,

%U 75,30,112,128,144,160,132,78,84,90,96,42,136,153,170,187,204,182

%N a(n) is the product of the frequencies of each digit of n up to and including that digit.

%H David A. Corneth, <a href="/A343645/b343645.txt">Table of n, a(n) for n = 1..10000</a>

%e a(10) = 2 as the digit 1 is the second digit 1 and the digit 0 is the first digit 0 giving 2*1.

%o (PARI) first(n) = my(v=vector(10), res=vector(n)); for(i=1, n, c=1; d=digits(i); for(i=1, #d, v[d[i]+1]++; c*=v[d[i]+1]); res[i] = c); res

%o (Python)

%o def aupto(limit):

%o   f, alst = [0 for i in range(10)], []

%o   for n in range(1, limit+1):

%o     p = 1

%o     for d in list(map(int, str(n))): f[d] += 1; p *= f[d]

%o     alst.append(p)

%o   return alst

%o print(aupto(66)) # _Michael S. Branicky_, Apr 23 2021

%K nonn,easy,base

%O 1,10

%A _David A. Corneth_, Apr 23 2021