A242954 -id:A242954 - cp's OEIS frontend

A243756 Triangle read by rows: T(n,k) = A242954(n)/(A242954(k) * A242954(n-k)).

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 4, 4, 1, 1, 1, 4, 4, 1, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 4, 4, 1, 4, 4, 4, 1, 1, 1, 4, 4, 1, 1, 4, 4, 1, 1, 1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4, 4, 4, 1, 4, 4, 4, 1, 4, 4, 4, 1

Offset: 0

Tom Edgar, Jun 09 2014

The exponent of T(n,k) is the number of 'carries' that occur when adding k and n-k in base 4 using the traditional addition algorithm.

If T(n,k) != 0 mod 4, then n dominates k in base 4.

			The triangle begins:
1;
1, 1;
1, 1, 1;
1, 1, 1, 1;
1, 4, 4, 4, 1;
1, 1, 4, 4, 1, 1;
1, 1, 1, 4, 1, 1, 1;
1, 1, 1, 1, 1, 1, 1, 1;
1, 4, 4, 4, 1, 4, 4, 4, 1;
1, 1, 4, 4, 1, 1, 4, 4, 1, 1;
1, 1, 1, 4, 1, 1, 1, 4, 1, 1, 1;
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1;

Tyler Ball, Tom Edgar, and Daniel Juda, Dominance Orders, Generalized Binomial Coefficients, and Kummer's Theorem, Mathematics Magazine, Vol. 87, No. 2, April 2014, pp. 135-143.
Tyler Ball and Daniel Juda, Dominance over N, Rose-Hulman Undergraduate Mathematics Journal, Vol. 13, No. 2, Fall 2013.
Tom Edgar and Michael Z. Spivey, Multiplicative functions, generalized binomial coefficients, and generalized Catalan numbers, Journal of Integer Sequences, Vol. 19 (2016), Article 16.1.6.

Cf. A082907, A234957, A242849, A242954.

m=50
T=[0]+[4^valuation(i, 4) for i in [1..m]]
Table=[[prod(T[1:i+1])/(prod(T[1:j+1])*prod(T[1:i-j+1])) for j in [0..i]] for i in [0..m-1]]
[x for sublist in Table for x in sublist]

T(n,k) = A242954(n)/(A242954(k) * A242954(n-k)).
T(n,k) = Product_{i=1..n} A234957(i)/(Product_{i=1..k} A234957(i)*Product_{i=1..n-k} A234957(i)).
T(n,k) = A234957(n)/n*(k/A234957(k)*T(n-1,k-1)+(n-k)/A234957(n-k)*T(n-1,k)).

A243757 a(n) = Product_{i=1..n} A060904(i).

Original entry on oeis.org

1, 1, 1, 1, 1, 5, 5, 5, 5, 5, 25, 25, 25, 25, 25, 125, 125, 125, 125, 125, 625, 625, 625, 625, 625, 15625, 15625, 15625, 15625, 15625, 78125, 78125, 78125, 78125, 78125, 390625, 390625, 390625, 390625, 390625, 1953125, 1953125, 1953125, 1953125, 1953125, 9765625

Offset: 0

Tom Edgar, Jun 10 2014

nonn

This is the generalized factorial for A060904.
a(0) = 1 as it represents the empty product.
a(n) is the largest power of 5 that divides n!, or the order of a 5-Sylow subgroup of the symmetric group of degree n. - David Radcliffe, Sep 03 2021

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
Tyler Ball, Tom Edgar, and Daniel Juda, Dominance Orders, Generalized Binomial Coefficients, and Kummer's Theorem, Mathematics Magazine, Vol. 87, No. 2, April 2014, pp. 135-143.

Cf. A027868, A060818, A060828, A060904, A242954.

a243757 n = a243757_list !! n
a243757_list = scanl (*) 1 a060904_list
-- Reinhard Zumkeller, Feb 04 2015

Table[Product[5^IntegerExponent[k, 5], {k, 1, n}], {n, 0, 20}] (* G. C. Greubel, Dec 24 2016 *)

a(n) = prod(k=1,n, 5^valuation(k,5)); \\ G. C. Greubel, Dec 24 2016

S=[0]+[5^valuation(i, 5) for i in [1..100]]
[prod(S[1:i+1]) for i in [0..99]]

a(n) = Product_{i=1..n} A060904(i).

a(n) = 5^(A027868(n)).

A243758 a(n) = Product_{i=1..n} A234959(i).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 6, 6, 6, 6, 6, 6, 36, 36, 36, 36, 36, 36, 216, 216, 216, 216, 216, 216, 1296, 1296, 1296, 1296, 1296, 1296, 7776, 7776, 7776, 7776, 7776, 7776, 279936, 279936, 279936, 279936, 279936, 279936, 1679616, 1679616, 1679616, 1679616, 1679616, 1679616, 10077696

Offset: 0

Tom Edgar, Jun 10 2014

This is the generalized factorial for A234959.

a(0) = 1 as it represents the empty product.

Reinhard Zumkeller, Table of n, a(n) for n = 0..1000
Tyler Ball, Tom Edgar, and Daniel Juda, Dominance Orders, Generalized Binomial Coefficients, and Kummer's Theorem, Mathematics Magazine, Vol. 87, No. 2, April 2014, pp. 135-143.

Cf. A060828, A060818, A234959, A242954, A243757.

a243758 n = a243758_list !! n
a243758_list = scanl (*) 1 a234959_list
-- Reinhard Zumkeller, Feb 09 2015

Table[Product[6^IntegerExponent[k, 6], {k, 1, n}], {n, 0, 20}] (* G. C. Greubel, Dec 24 2016 *)

valp(n,p)=my(s); while(n\=p, s+=n); s
a(n)=6^valp(n,6) \\ Charles R Greathouse IV, Oct 03 2016

S=[0]+[6^valuation(i,6) for i in [1..100]]
[prod(S[1:i+1]) for i in [0..99]]

a(n) = Product_{i=1..n} A234959(i).

a(n) = 6^(A054895(n)).

A087069 a(n) = Sum_{k >= 0} floor(n/(4^k)).

Original entry on oeis.org

0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 21, 22, 23, 24, 26, 27, 28, 29, 31, 32, 33, 34, 36, 37, 38, 39, 42, 43, 44, 45, 47, 48, 49, 50, 52, 53, 54, 55, 57, 58, 59, 60, 63, 64, 65, 66, 68, 69, 70, 71, 73, 74, 75, 76, 78, 79, 80, 81, 85, 86, 87, 88, 90, 91, 92, 93

Offset: 0

Clark Kimberling, Aug 07 2003

nonn

			a(4) = 4 + floor(4/4) + floor(4/16) + floor(4/64) + ... = 5.

Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Cf. A005187, A054893, A242954.

Essentially partial sums of A115362.

import Data.List (unfoldr)
a087069 =
   sum . unfoldr (\x -> if x == 0 then Nothing else Just (x, x `div` 4))
-- Reinhard Zumkeller, Apr 22 2011

Table[Sum[Floor[n/4^k], {k, 0, 1000}], {n, 0, 50}] (* G. C. Greubel, Oct 11 2017 *)

for(n=0,50, print1(sum(k=0,1000, floor(n/4^k)), ", ")) \\ G. C. Greubel, Oct 11 2017

a(n) = Sum_{k>=0} A030308(n,k)*A000975(k+1). - Philippe Deléham, Oct 16 2011
a(n) = A054893(4*n). - Vaclav Kotesovec, May 28 2014
G.f.: (1/(1 - x))*Sum_{k>=0} x^(4^k)/(1 - x^(4^k)). - Ilya Gutkovskiy, Mar 15 2018

cp's OEIS Frontend

A243756 Triangle read by rows: T(n,k) = A242954(n)/(A242954(k) * A242954(n-k)).

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A243757 a(n) = Product_{i=1..n} A060904(i).

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A243758 a(n) = Product_{i=1..n} A234959(i).

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Author

Keywords

Comments

Links

Crossrefs

Programs

Haskell

Mathematica

PARI

Sage

Formula

A087069 a(n) = Sum_{k >= 0} floor(n/(4^k)).

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Author

Keywords

Examples

Links

Crossrefs

Programs

Haskell

Mathematica

PARI

Formula