A231502 -id:A231502 - cp's OEIS frontend

A360189 Triangle T(n,k), n>=0, 0<=k<=floor(log_2(n+1)), read by rows: T(n,k) = number of nonnegative integers <= n having binary weight k.

1, 1, 1, 1, 2, 1, 2, 1, 1, 3, 1, 1, 3, 2, 1, 3, 3, 1, 3, 3, 1, 1, 4, 3, 1, 1, 4, 4, 1, 1, 4, 5, 1, 1, 4, 5, 2, 1, 4, 6, 2, 1, 4, 6, 3, 1, 4, 6, 4, 1, 4, 6, 4, 1, 1, 5, 6, 4, 1, 1, 5, 7, 4, 1, 1, 5, 8, 4, 1, 1, 5, 8, 5, 1, 1, 5, 9, 5, 1, 1, 5, 9, 6, 1, 1, 5, 9, 7, 1

Offset: 0

Alois P. Heinz, Mar 04 2023

T(n,k) is defined for all n >= 0 and k >= 0. Terms that are not in the triangle are zero.

			T(6,2) = 3: 3, 5, 6, or in binary: 11_2, 101_2, 110_2.
T(15,3) = 4: 7, 11, 13, 14, or in binary: 111_2, 1011_2, 1101_2, 1110_2.
Triangle T(n,k) begins:
  1;
  1, 1;
  1, 2;
  1, 2, 1;
  1, 3, 1;
  1, 3, 2;
  1, 3, 3;
  1, 3, 3, 1;
  1, 4, 3, 1;
  1, 4, 4, 1;
  1, 4, 5, 1;
  1, 4, 5, 2;
  1, 4, 6, 2;
  1, 4, 6, 3;
  1, 4, 6, 4;
  1, 4, 6, 4, 1;
  ...

Alois P. Heinz, Rows n = 0..2^12-1, flattened
Peter J. Taylor, Closed form for Sum_{k=0..n} [wt(k) = m] where wt(n) is the binary weight of n, answer to question on MathOverflow (2024).
Wikipedia, Iverson bracket

Columns k=0-2 give: A000012, A029837(n+1) = A113473(n) for n>0, A340068(n+1).
Last elements of rows give A090996(n+1).
Cf. A000027, A000120, A000225, A000788, A006046, A007318, A116520, A116522, A116525, A116526, A130665, A130667, A161342, A231500, A231501, A231502, A272020, A361257.

b:= proc(n) option remember; `if`(n<0, 0,
      b(n-1)+x^add(i, i=Bits[Split](n)))
    end:
T:= n-> (p-> seq(coeff(p, x, i), i=0..degree(p)))(b(n)):
seq(T(n), n=0..23);

T(n,k) = my(v1); v1 = Vecrev(binary(n+1)); v1 = Vecrev(select(x->(x>0),v1,1)); sum(j=0, min(k,#v1-1), binomial(v1[j+1]-1,k-j)) \\ Mikhail Kurkov, Nov 27 2024

T(n,k) = T(n-1,k) + [A000120(n) = k] where [] is the Iverson bracket and T(n,k) = 0 for n<0.
T(2^n-1,k) = A007318(n,k) = binomial(n,k).
T(n,floor(log_2(n+1))) = A090996(n+1).
Sum_{k>=0} T(n,k) = n+1.
Sum_{k>=0} k * T(n,k) = A000788(n).
Sum_{k>=0} k^2 * T(n,k) = A231500(n).
Sum_{k>=0} k^3 * T(n,k) = A231501(n).
Sum_{k>=0} k^4 * T(n,k) = A231502(n).
Sum_{k>=0} 2^k * T(n,k) = A006046(n+1).
Sum_{k>=0} 3^k * T(n,k) = A130665(n).
Sum_{k>=0} 4^k * T(n,k) = A116520(n+1).
Sum_{k>=0} 5^k * T(n,k) = A130667(n+1).
Sum_{k>=0} 6^k * T(n,k) = A116522(n+1).
Sum_{k>=0} 7^k * T(n,k) = A161342(n+1).
Sum_{k>=0} 8^k * T(n,k) = A116526(n+1).
Sum_{k>=0} 10^k * T(n,k) = A116525(n+1).
Sum_{k>=0} n^k * T(n,k) = A361257(n).
T(n,k) = Sum_{j=0..min(k, A000120(n+1)-1)} binomial(A272020(n+1,j+1)-1,k-j) for n >= 0, k >= 0 (see Peter J. Taylor link). - Mikhail Kurkov, Nov 27 2024

A231500 a(n) = Sum_{i=0..n} wt(i)^2, where wt(i) = A000120(i).

Original entry on oeis.org

0, 1, 2, 6, 7, 11, 15, 24, 25, 29, 33, 42, 46, 55, 64, 80, 81, 85, 89, 98, 102, 111, 120, 136, 140, 149, 158, 174, 183, 199, 215, 240, 241, 245, 249, 258, 262, 271, 280, 296, 300, 309, 318, 334, 343, 359, 375, 400, 404, 413, 422, 438, 447, 463, 479, 504, 513, 529, 545, 570, 586, 611, 636, 672, 673, 677, 681, 690, 694

Offset: 0

N. J. A. Sloane, Nov 12 2013

Stolarsky (1977) has an extensive bibliography.

Amiram Eldar, Table of n, a(n) for n = 0..10000 (terms 0..1024 from Ivan Neretin)
Jean Coquet, Power sums of digital sums, J. Number Theory, Vol. 22, No. 2 (1986), pp. 161-176.
P. J. Grabner, P. Kirschenhofer, H. Prodinger and R. F. Tichy, On the moments of the sum-of-digits function, PDF, Applications of Fibonacci numbers, Vol. 5 (St. Andrews, 1992), Kluwer Acad. Publ., Dordrecht, 1993, pp. 263-271; alternative link.
J.-L. Mauclaire and Leo Murata, On q-additive functions. I, Proc. Japan Acad. Ser. A Math. Sci., Vol. 59, No. 6 (1983), pp. 274-276.
J.-L. Mauclaire and Leo Murata, On q-additive functions. II, Proc. Japan Acad. Ser. A Math. Sci., Vol. 59, No. 9 (1983), pp. 441-444.
Kenneth B. Stolarsky, Power and exponential sums of digital sums related to binomial coefficient parity, SIAM J. Appl. Math., Vol. 32, No. 4 (1977), pp. 717-730.
J. R. Trollope, An explicit expression for binary digital sums, Math. Mag., Vol. 41, No. 1 (1968), pp. 21-25.

Cf. A000120, A000788, A231501, A231502, A360189.

digsum:=proc(n,B) local a; a := convert(n, base, B):
add(a[i], i=1..nops(a)): end;
f:=proc(n,k,B) global digsum; local i;
add( digsum(i,B)^k,i=0..n); end;
[seq(f(n,1,2),n=0..100)]; #A000788
[seq(f(n,2,2),n=0..100)]; #A231500
[seq(f(n,3,2),n=0..100)]; #A231501
[seq(f(n,4,2),n=0..100)]; #A231502

FoldList[#1 + DigitCount[#2, 2, 1]^2 &, 0, Range[1, 68]] (* Ivan Neretin, May 21 2015 *)

a(n) = sum(i=0, n, hammingweight(i)^2); \\ Michel Marcus, Sep 20 2017

Stolarsky (1977) studies the asymptotics.
a(n) ~ n * (log(n)/(2*log(2)))^2 + O(n*log(n)) (Stolarsky, 1977). - Amiram Eldar, Jan 20 2022
a(n) = Sum_{k=0..floor(log_2(n+1))} k^2 * A360189(n,k). - Alois P. Heinz, Mar 06 2023

A231501 a(n) = Sum_{i=0..n} wt(i)^3, where wt() = A000120().

Original entry on oeis.org

0, 1, 2, 10, 11, 19, 27, 54, 55, 63, 71, 98, 106, 133, 160, 224, 225, 233, 241, 268, 276, 303, 330, 394, 402, 429, 456, 520, 547, 611, 675, 800, 801, 809, 817, 844, 852, 879, 906, 970, 978, 1005, 1032, 1096, 1123, 1187, 1251, 1376, 1384, 1411, 1438, 1502, 1529, 1593, 1657, 1782, 1809, 1873, 1937, 2062, 2126, 2251

Offset: 0

N. J. A. Sloane, Nov 12 2013

Amiram Eldar, Table of n, a(n) for n = 0..10000
Jean Coquet, Power sums of digital sums, J. Number Theory, Vol. 22, No. 2 (1986), pp. 161-176.
P. J. Grabner, P. Kirschenhofer, H. Prodinger and R. F. Tichy, On the moments of the sum-of-digits function, PDF, Applications of Fibonacci numbers, Vol. 5 (St. Andrews, 1992), Kluwer Acad. Publ., Dordrecht, 1993, pp. 263-271; alternative link.
J.-L. Mauclaire and Leo Murata, On q-additive functions. I, Proc. Japan Acad. Ser. A Math. Sci., Vol. 59, No. 6 (1983), pp. 274-276.
J.-L. Mauclaire and Leo Murata, On q-additive functions. II, Proc. Japan Acad. Ser. A Math. Sci., Vol. 59, No. 9 (1983), pp. 441-444.
Kenneth B. Stolarsky, Power and exponential sums of digital sums related to binomial coefficient parity, SIAM J. Appl. Math., Vol. 32, No. 4 (1977), pp. 717-730.
J. R. Trollope, An explicit expression for binary digital sums, Math. Mag., Vol. 41, No. 1 (1968), pp. 21-25.

Cf. A000120, A000788, A231500, A231502, A360189.

Accumulate @ (Table[DigitCount[n, 2, 1], {n, 0, 60}]^3) (* Amiram Eldar, Jan 20 2022 *)

a(n) = sum(i=0, n, hammingweight(i)^3); \\ Michel Marcus, Sep 20 2017

a(n) ~ n * (log(n)/(2*log(2)))^3 + O(n*log(n)^2) (Stolarsky, 1977). - Amiram Eldar, Jan 20 2022

a(n) = Sum_{k=0..floor(log_2(n+1))} k^3 * A360189(n,k). - Alois P. Heinz, Mar 06 2023

cp's OEIS Frontend

A360189 Triangle T(n,k), n>=0, 0<=k<=floor(log_2(n+1)), read by rows: T(n,k) = number of nonnegative integers <= n having binary weight k.

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A231500 a(n) = Sum_{i=0..n} wt(i)^2, where wt(i) = A000120(i).

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A231501 a(n) = Sum_{i=0..n} wt(i)^3, where wt() = A000120().

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Mathematica

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