A033093 -id:A033093 - cp's OEIS frontend

A033111 Number of 9's when n is written in base b for 2<=b<=n+1.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 1, 3, 1, 2, 2, 2, 1, 3, 1, 2, 2, 3, 1, 3, 1, 3, 2, 2, 1, 4, 1, 3, 2, 3, 1, 3, 2, 3, 2, 2, 1, 6, 1, 2, 2, 3, 2, 4, 1, 3, 2, 4, 1, 5, 1, 2, 3, 3, 2, 4, 1, 5, 3

Offset: 1

Clark Kimberling

Cf. A033093, A033095, A033097, A033099, A033101, A033103, A033105, A033107, A033109, A033112.

f[n_] := Count[Flatten@ Table[ IntegerDigits[n, b], {b, 2, n + 1}], 9]; Array[f, 90](* Robert G. Wilson v, Nov 14 2012 *)

A309891 a(n) is the total number of trailing zeros in the representations of n over all bases b >= 2.

Original entry on oeis.org

0, 1, 1, 3, 1, 3, 1, 5, 3, 3, 1, 6, 1, 3, 3, 8, 1, 6, 1, 6, 3, 3, 1, 9, 3, 3, 5, 6, 1, 7, 1, 10, 3, 3, 3, 11, 1, 3, 3, 9, 1, 7, 1, 6, 6, 3, 1, 13, 3, 6, 3, 6, 1, 9, 3, 9, 3, 3, 1, 12, 1, 3, 6, 14, 3, 7, 1, 6, 3, 7, 1, 15, 1, 3, 6, 6, 3, 7, 1, 13, 8, 3, 1, 12

Offset: 1

Rémy Sigrist, Aug 21 2019

a(n) depends only on the prime signature of n.

a(n) is the sum of the k-adic valuations of n for k >= 2. - Friedjof Tellkamp, Jan 25 2025

			For n = 12: 12 has 2 trailing zeros in base 2 (1100), 1 trailing zero in bases 3, 4, 6 and 12 (110, 30, 20, 10) and no trailing zero in other bases, hence a(12) = 1*2 + 4*1 = 6.

Antti Karttunen, Table of n, a(n) for n = 1..16384
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..100000
Index entries for sequences computed from exponents in factorization of n

Cf. A001221, A006218, A007814, A007949, A033093, A056239, A112765, A122841, A169594, A214411, A235127, A244413, A286561, A293514, A369180.
Cf. A111003.
First differences of A078632.

Table[DivisorSum[n, IntegerExponent[n, #] &, # > 1 &], {n, 84}] (* Jon Maiga, Aug 25 2019 *)

a(n) = sumdiv(n, d, if (d>1, valuation(n,d), 0))

a(n) = {if(n == 1, return(0)); my(f = factor(n)[, 2], res = 0, t = 2, of = f, nf = f >> 1, nd(v) = prod(i = 1, #v, v[i] + 1)); while(Set(of) != [0], res += (nd(of) - nd(nf)) * (t-1); of = nf; t++; nf = f \ t); res} \\ David A. Corneth, Aug 22 2019

a(n) = Sum_{d|n, d>1} A286561(n,d), where A286561 gives the d-valuation of n.
a(p) = 1 for any prime number p.
a(p^k) = A006218(k) for any k >= 0 and any prime number p.
a(n) = 2^A001221(n) - 1 for any squarefree number n.
a(n) = 3 for any semiprime number n.
a(m*n) >= a(m) + a(n).
a(n) >= A007814(n) + A007949(n) + A235127(n) + A112765(n) + A122841(n) + A214411(n) + A244413(n).
a(n) = A056239(A293514(n)). - Antti Karttunen, Aug 22 2019
a(n) <= A033093(n). - Michel Marcus, Aug 22 2019
a(n) = A169594(n) - 1. - Jon Maiga, Aug 25 2019
From Friedjof Tellkamp, Feb 27 2024: (Start)
G.f.: Sum_{k>=2, j>=1} x^(k^j)/(1-x^(k^j)).
Dirichlet g.f.: zeta(s) * Sum_{k>=1} (zeta(k*s) - 1).
Sum_{n>=1} a(n)/n^2 = Pi^2/8 (A111003). (End)

A077268 Number of bases in which n requires at least one zero to be written.

Original entry on oeis.org

0, 1, 1, 2, 2, 3, 1, 3, 3, 4, 3, 5, 2, 3, 3, 4, 3, 6, 4, 6, 4, 3, 2, 7, 3, 4, 5, 7, 4, 7, 2, 6, 5, 5, 6, 8, 4, 5, 5, 8, 3, 7, 2, 5, 6, 4, 3, 9, 4, 7, 7, 7, 4, 9, 6, 8, 4, 4, 3, 11, 3, 4, 5, 7, 7, 9, 4, 6, 6, 9, 4, 11, 5, 6, 8, 7, 7, 9, 4, 9, 6, 6, 5, 12, 6, 5, 5, 9, 4, 11, 5, 6, 4, 4, 5, 11, 4, 7, 8, 10, 6

Offset: 1

Henry Bottomley, Nov 01 2002

			a(9)=3 since it requires zeros when written in bases 2, 3 or 9 (as 1001, 100 or 10 respectively).

Eric M. Schmidt, Table of n, a(n) for n = 1..10000

Cf. A033093, A062842, A077266, A077267.

a(n) = sum(i=2, n, ! vecmin(digits(n, i))); \\ Michel Marcus, Jul 09 2014

def A077268(n) : return sum(0 in n.digits(m) for m in range(2,n+1)) # Eric M. Schmidt, Jul 09 2014

A077266 Triangle of number of zeros when n is written in base k (2 <= k <= n).

Original entry on oeis.org

1, 0, 1, 2, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 3, 0, 1, 0, 0, 0, 1, 2, 2, 0, 0, 0, 0, 0, 1, 2, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 1, 0, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

Offset: 2

Henry Bottomley, Nov 01 2002

			Rows start:
  1;
  0,1;
  2,0,1;
  1,0,0,1;
  1,1,0,0,1;
  0,0,0,0,0,1;
  3,0,1,0,0,0,1;
  2,2,0,0,0,0,0,1;
  etc.
9 can be written in bases 2-9 as: 1001, 100, 21, 14, 13, 12, 11 and 10, in which case the numbers of zeros are 2,2,0,0,0,0,0,1.

Harvey P. Dale, Table of n, a(n) for n = 2..1000

Columns include A023416 and A077267. Row sums are A033093, row maxima are A062842, number of positive terms in each row are A077268.

Table[Count[#,0]&/@IntegerDigits[n,Range[2,n]],{n,2,15}]//Flatten (* Harvey P. Dale, Jun 02 2025 *)

T(n, k) = #select(x->(x==0), digits(n, k));
row(n) = vector(n-1, k, T(n,k+1));
tabl(nn) = for (n=2, nn, print(row(n))); \\ Michel Marcus, Sep 02 2020

T(nk, k)=T(n, k)+1; T(nk+m, k)=T(n, k) if 0

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A033111 Number of 9's when n is written in base b for 2<=b<=n+1.

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A309891 a(n) is the total number of trailing zeros in the representations of n over all bases b >= 2.

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A077268 Number of bases in which n requires at least one zero to be written.

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A077266 Triangle of number of zeros when n is written in base k (2 <= k <= n).

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