cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A323963 Number of defective (binary) heaps on n elements with exactly seven defects.

Original entry on oeis.org

0, 210, 7616, 185460, 4200960, 77887920, 1310267904, 21025461600, 314958758400, 4765553385120, 69086614338560, 1013373907056960, 14714554645140480, 212868974122848000, 3168605413206097920, 45787509175434048000, 705241846739554713600, 10297540417675899801600
Offset: 7

Views

Author

Alois P. Heinz, Feb 09 2019

Keywords

Comments

Or number of permutations p of [n] having exactly seven indices i in {1,...,n} such that p(i) > p(floor(i/2)).

Crossrefs

Column k=7 of A306343.
Cf. A056971.

A323964 Number of defective (binary) heaps on n elements with exactly eight defects.

Original entry on oeis.org

0, 896, 32460, 1201920, 29987760, 705522048, 14197154400, 264121228800, 4765553385120, 80958196300800, 1386261729792960, 22797317814635520, 378396940680172800, 6210934579834490880, 101592763596409536000, 1694705349980956262400, 27653450672540750745600
Offset: 8

Views

Author

Alois P. Heinz, Feb 09 2019

Keywords

Comments

Or number of permutations p of [n] having exactly eight indices i in {1,...,n} such that p(i) > p(floor(i/2)).

Crossrefs

Column k=8 of A306343.
Cf. A056971.

A323965 Number of defective (binary) heaps on n elements with exactly nine defects.

Original entry on oeis.org

0, 3360, 190800, 6837600, 239978112, 6268548000, 153775564800, 3365570435040, 69086614338560, 1386261729792960, 26344715667079680, 502986050203680000, 9251596509192069120, 171657357483560256000, 3142069546022259916800, 57414248711716723200000
Offset: 9

Views

Author

Alois P. Heinz, Feb 09 2019

Keywords

Comments

Or number of permutations p of [n] having exactly nine indices i in {1,...,n} such that p(i) > p(floor(i/2)).

Crossrefs

Column k=9 of A306343.
Cf. A056971.

A323966 Number of defective (binary) heaps on n elements with exactly ten defects.

Original entry on oeis.org

0, 19200, 947760, 49680576, 1744142400, 60169824000, 1646888944800, 42633973724160, 1013373907056960, 22797317814635520, 502986050203680000, 10556482426015426560, 222685725334400064000, 4535040919258899456000, 92995172484979478630400, 1880492299058130490163200
Offset: 10

Views

Author

Alois P. Heinz, Feb 09 2019

Keywords

Comments

Or number of permutations p of [n] having exactly ten indices i in {1,...,n} such that p(i) > p(floor(i/2)).

Crossrefs

Column k=10 of A306343.
Cf. A056971.

A324062 Number of defective (binary) heaps on n elements where one ancestor-successor pair does not have the correct order.

Original entry on oeis.org

0, 0, 1, 2, 6, 16, 60, 240, 840, 3584, 16800, 96000, 475200, 3041280, 19219200, 153753600, 864864000, 6560153600, 47048601600, 439934976000, 3192583680000, 31434670080000, 280947363840000, 3296449069056000, 27139515346944000, 308787374614118400
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly one pair (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Examples

			a(4) = 6: 3241, 3412, 3421, 4123, 4132, 4213.
a(5) = 16: 43512, 43521, 45123, 45132, 45213, 45231, 45312, 45321, 52314, 52341, 52413, 52431, 53124, 53142, 53214, 53241.
(The examples use max-heaps.)
		

Crossrefs

Column k=1 of A306393.
Cf. A056971.

Programs

  • Maple
    b:= proc(u, o) option remember; local n, g, l; n:= u+o;
          if n=0 then 1
        else g:= 2^ilog2(n); l:= min(g-1, n-g/2); expand(
             add(x^(n-j)*add(binomial(j-1, i)*binomial(n-j, l-i)*
             b(i, l-i)*b(j-1-i, n-l-j+i), i=0..min(j-1, l)), j=1..u)+
             add(x^(j-1)*add(binomial(j-1, i)*binomial(n-j, l-i)*
             b(l-i, i)*b(n-l-j+i, j-1-i), i=0..min(j-1, l)), j=1..o))
          fi
        end:
    a:= n-> coeff(b(n, 0), x, 1):
    seq(a(n), n=0..25);
  • Mathematica
    b[u_, o_] := b[u, o] = Module[{n, g, l}, n = u + o; If[n == 0, 1,
         g = 2^(Length[IntegerDigits[n, 2]]-1); l = Min[g-1, n-g/2]; Expand[
         Sum[ x^(n - j)*Sum[Binomial[j - 1, i]*Binomial[n - j, l - i]*
         b[i, l-i]*b[j-1-i, n-l-j+i], {i, 0, Min[j - 1, l]}], {j, 1, u}] +
         Sum[x^(j-1)*Sum[Binomial[j-1, i]*Binomial[n - j, l - i]*
         b[l-i, i]*b[n-l-j+i, j-1-i], {i, 0, Min[j-1, l]}], {j, 1, o}]]]];
    a[n_] := Coefficient[b[n, 0], x, 1];
    a /@ Range[0, 25] (* Jean-François Alcover, Apr 22 2021, after Alois P. Heinz *)

A324063 Number of defective (binary) heaps on n elements where two ancestor-successor pairs do not have the correct order.

Original entry on oeis.org

0, 0, 0, 2, 6, 24, 100, 480, 1890, 8960, 47040, 288000, 1584000, 10644480, 74131200, 615014400, 3783780000, 29520691200, 230015385600, 2199674880000, 17239951872000, 172890685440000, 1660143513600000, 19778694414336000, 174145223476224000, 2007117934991769600
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly two pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Crossrefs

Column k=2 of A306393.
Cf. A056971.

A324064 Number of defective (binary) heaps on n elements where three ancestor-successor pairs do not have the correct order.

Original entry on oeis.org

0, 0, 0, 0, 6, 24, 120, 640, 3150, 16128, 94080, 614400, 3801600, 26864640, 203174400, 1757184000, 11783772000, 95122227200, 794598604800, 7821066240000, 65767223808000, 675845406720000, 6895980748800000, 83909612666880000, 784784318782464000
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly three pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Crossrefs

Column k=3 of A306393.
Cf. A056971.

A324065 Number of defective (binary) heaps on n elements where four ancestor-successor pairs do not have the correct order.

Original entry on oeis.org

0, 0, 0, 0, 3, 24, 120, 720, 4200, 24192, 151200, 1056000, 7286400, 54743040, 442041600, 3997593600, 29081052000, 244365721600, 2164235673600, 21996748800000, 197620929792000, 2090405560320000, 22475789107200000, 280198170869760000, 2772753817946112000
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly four pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Crossrefs

Column k=4 of A306393.
Cf. A056971.

A324066 Number of defective (binary) heaps on n elements where five ancestor-successor pairs do not have the correct order.

Original entry on oeis.org

0, 0, 0, 0, 0, 16, 120, 720, 4830, 31360, 211680, 1555200, 11880000, 95293440, 815443200, 7687680000, 60432372000, 530552422400, 4945330790400, 51912327168000, 496766020608000, 5425624055808000, 61093281300480000, 781258429366272000, 8157685988035584000
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly five pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Crossrefs

Column k=5 of A306393.
Cf. A056971.

A324067 Number of defective (binary) heaps on n elements where six ancestor-successor pairs do not have the correct order.

Original entry on oeis.org

0, 0, 0, 0, 0, 8, 100, 720, 5040, 36736, 268800, 2073600, 17186400, 147502080, 1331616000, 13047091200, 110053944000, 1011903692800, 9874978713600, 106953080832000, 1086116967936000, 12275238666240000, 144074916311040000, 1890064025321472000
Offset: 0

Views

Author

Alois P. Heinz, Feb 13 2019

Keywords

Comments

Or number of permutations p of [n] having exactly six pairs (i,j) in {1,...,n} X {1,...,floor(log_2(i))} such that p(i) > p(floor(i/2^j)).

Crossrefs

Column k=6 of A306393.
Cf. A056971.
Previous Showing 31-40 of 66 results. Next