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.

Showing 1-10 of 10 results.

A212864 Number of nondecreasing sequences of n 1..4 integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 2, 3, 5, 6, 9, 12, 15, 17, 22, 26, 30, 34, 40, 45, 51, 56, 63, 70, 77, 83, 92, 100, 108, 116, 126, 135, 145, 154, 165, 176, 187, 197, 210, 222, 234, 246, 260, 273, 287, 300, 315, 330, 345, 359, 376, 392, 408, 424, 442, 459, 477, 494, 513, 532, 551, 569, 590, 610, 630, 650
Offset: 1

Views

Author

R. H. Hardin, May 29 2012

Keywords

Comments

Column 4 of A212868.

Examples

			All solutions for n=8:
..2....2....2....2....2....2....3....2....2....3....2....2....2....3....3
..2....3....2....2....2....2....3....2....3....3....2....3....2....4....3
..3....3....2....2....2....2....3....3....4....3....2....3....2....4....3
..3....3....2....2....2....2....3....3....4....3....3....3....3....4....4
..3....3....3....2....2....2....3....3....4....3....4....3....3....4....4
..3....3....4....2....2....3....3....4....4....3....4....3....3....4....4
..3....3....4....3....2....3....4....4....4....3....4....4....4....4....4
..4....3....4....4....3....3....4....4....4....4....4....4....4....4....4
		

Crossrefs

Cf. A212868.

Formula

Empirical: a(n) = a(n-1) + a(n-3) - a(n-5) - a(n-7) + a(n-8).
Empirical g.f.: x^2*(2 + x + 2*x^2 - x^3) / ((1 - x)^3*(1 + x)*(1 + x^2)*(1 + x + x^2)). - Colin Barker, Jul 21 2018

A212865 Number of nondecreasing sequences of n 1..5 integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 5, 9, 15, 22, 32, 40, 59, 74, 97, 124, 159, 188, 229, 260, 301, 347, 415, 477, 559, 630, 715, 801, 897, 987, 1106, 1214, 1342, 1471, 1623, 1760, 1934, 2099, 2287, 2475, 2683, 2878, 3116, 3334, 3581, 3832, 4115, 4377, 4681, 4968, 5283, 5605, 5965, 6310, 6707
Offset: 1

Views

Author

R. H. Hardin, May 29 2012

Keywords

Comments

Column 5 of A212868.

Examples

			Some solutions for n=8:
..2....3....2....2....3....2....2....2....3....2....4....2....3....4....2....2
..2....3....2....3....3....4....5....3....3....2....4....2....3....5....3....2
..2....3....2....3....3....4....5....4....4....3....4....3....3....5....3....2
..2....3....3....3....3....4....5....4....4....3....4....3....3....5....3....4
..2....3....5....3....3....4....5....4....5....4....4....3....3....5....4....4
..3....4....5....3....3....4....5....4....5....5....4....4....3....5....4....5
..3....5....5....3....3....4....5....5....5....5....4....4....4....5....5....5
..3....5....5....3....4....5....5....5....5....5....5....4....4....5....5....5
		

Formula

Empirical: a(n) = 2*a(n-1) -2*a(n-3) +a(n-5) +2*a(n-6) -2*a(n-7) -2*a(n-8) +2*a(n-9) +a(n-10) -a(n-12) -2*a(n-13) +2*a(n-14) +2*a(n-15) -2*a(n-16) -a(n-17) +2*a(n-19) +a(n-20) -4*a(n-21) +a(n-22) +2*a(n-23) -a(n-25) -2*a(n-26) +2*a(n-27) +2*a(n-28) -2*a(n-29) -a(n-30) +a(n-32) +2*a(n-33) -2*a(n-34) -2*a(n-35) +2*a(n-36) +a(n-37) -2*a(n-39) +2*a(n-41) -a(n-42).
If the above empirical recurrence by R. H. Hardin is correct, then the denominator of the g.f. (that determines the above recurrence) equals (1-x)^2*(1-x^2)*(1-x^12)*(1-x^15)*(1-x^20)/((1-x^4)*(1-x^5)). - Petros Hadjicostas, Sep 09 2019

A212866 Number of nondecreasing sequences of n 1..6 integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 7, 16, 29, 52, 82, 122, 182, 259, 363, 492, 648, 816, 1018, 1268, 1586, 1973, 2419, 2904, 3452, 4063, 4762, 5543, 6421, 7393, 8487, 9700, 11052, 12543, 14183, 15960, 17915, 20023, 22303, 24760, 27422, 30279, 33373, 36697, 40284, 44131, 48250, 52614
Offset: 1

Views

Author

R. H. Hardin, May 29 2012

Keywords

Examples

			Some solutions for n=8:
..2....3....2....2....2....2....3....3....2....2....2....2....4....5....3....2
..2....3....2....2....3....5....3....4....2....3....2....2....4....5....3....3
..2....3....3....2....3....6....4....4....3....4....2....3....4....5....3....3
..3....3....3....2....3....6....4....4....3....4....2....3....5....5....3....3
..3....3....4....2....6....6....4....5....4....4....2....4....6....6....3....3
..3....3....5....2....6....6....4....6....4....4....2....5....6....6....5....3
..4....3....6....4....6....6....4....6....5....5....2....5....6....6....6....3
..4....4....6....5....6....6....5....6....6....5....5....5....6....6....6....3
		

Crossrefs

Column 6 of A212868.

Programs

  • Maple
    S6:= combinat:-powerset({$2..6}):
    f:= proc(n) local s,t,G,S,i,j,T;
      t:= 0:
      for S in S6 do
        G:= coeff(mul(add(x^i*y^(i*j),i=0..n),j=S),x,n);
        T:= select(s -> S = select(k -> s mod k <> 0, {$2..6}), [$2*n..6*n]);
        t:= t + add(coeff(G,y,s),s= T);
      od;
      t
    end proc:
    map(f, [$1..50]); # Robert Israel, Nov 23 2023

Formula

Empirical: a(n) = 3*a(n-1) -2*a(n-2) -2*a(n-3) +2*a(n-4) +a(n-5) +a(n-6) -4*a(n-7) +4*a(n-9) -a(n-10) -a(n-11) -a(n-12) -a(n-13) +4*a(n-14) -4*a(n-16) +a(n-17) +a(n-18) +2*a(n-19) -a(n-20) -5*a(n-21) +5*a(n-22) +a(n-23) -2*a(n-24) -a(n-25) -a(n-26) +4*a(n-27) -4*a(n-29) +a(n-30) +a(n-31) +a(n-32) +a(n-33) -4*a(n-34) +4*a(n-36) -a(n-37) -a(n-38) -2*a(n-39) +2*a(n-40) +2*a(n-41) -3*a(n-42) +a(n-43).

A212867 Number of nondecreasing sequences of n 1..7 integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 12, 29, 59, 112, 199, 319, 503, 733, 1067, 1508, 2104, 2827, 3801, 4974, 6404, 8054, 10101, 12573, 15680, 19309, 23586, 28399, 33966, 40235, 47554, 55866, 65509, 76417, 88971, 103077, 119201, 137210, 157549, 180024, 205015, 232280, 262333, 294930
Offset: 1

Views

Author

R. H. Hardin May 29 2012

Keywords

Comments

Column 7 of A212868

Examples

			Some solutions for n=8
..2....2....4....2....3....2....4....2....3....2....2....3....3....5....3....2
..2....4....4....2....3....4....4....2....4....2....2....4....3....5....3....3
..3....4....4....2....3....4....4....2....4....3....2....5....3....6....3....7
..4....5....4....2....3....4....4....2....4....3....3....5....4....6....5....7
..4....6....5....4....6....4....4....3....4....4....3....5....7....6....5....7
..5....6....5....4....6....5....5....3....6....4....3....6....7....6....5....7
..5....6....6....5....7....5....7....4....6....6....3....6....7....6....6....7
..6....6....7....6....7....5....7....5....7....7....7....7....7....7....7....7
		

A212870 Number of nondecreasing sequences of 3 1..n integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 0, 1, 3, 9, 16, 29, 43, 64, 92, 127, 168, 219, 281, 355, 435, 531, 638, 762, 901, 1057, 1230, 1420, 1628, 1858, 2107, 2380, 2674, 2992, 3338, 3707, 4099, 4524, 4976, 5465, 5975, 6516, 7092, 7704, 8348, 9025, 9744, 10495, 11289, 12125, 12994, 13907, 14859
Offset: 1

Views

Author

R. H. Hardin, May 29 2012

Keywords

Comments

Row 3 of A212868.

Examples

			Some solutions for n=8
..3....5....3....2....6....2....6....7....3....3....2....4....3....6....3....5
..7....7....5....5....7....2....6....8....5....3....3....7....4....6....3....8
..7....7....5....6....7....7....8....8....6....4....8....7....4....7....8....8
		

Crossrefs

Cf. A212868.

A212871 Number of nondecreasing sequences of 4 1..n integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 0, 1, 5, 15, 29, 59, 103, 168, 259, 386, 553, 772, 1043, 1401, 1832, 2356, 2980, 3729, 4622, 5680, 6872, 8263, 9872, 11716, 13767, 16122, 18765, 21707, 25010, 28650, 32686, 37173, 42036, 47466, 53375, 59783, 66728, 74355, 82632, 91519, 101150
Offset: 1

Views

Author

R. H. Hardin May 29 2012

Keywords

Comments

Row 4 of A212868

Examples

			Some solutions for n=8
..2....3....4....3....4....3....2....4....4....2....2....3....4....2....2....2
..3....3....7....5....5....3....5....4....6....3....4....5....6....2....5....5
..6....5....7....7....5....4....6....5....7....4....5....5....8....3....5....5
..8....5....7....7....5....7....8....6....8....8....8....6....8....4....7....5
		

A212872 Number of nondecreasing sequences of 5 1..n integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 0, 2, 6, 22, 52, 112, 212, 376, 640, 1011, 1560, 2293, 3328, 4711, 6524, 8765, 11703, 15273, 19886, 25459, 32224, 40193, 50022, 61521, 75059, 90825, 109479, 130520, 155415, 183229, 215594, 252070, 293377, 340266, 393232, 451522, 517139, 590227
Offset: 1

Views

Author

R. H. Hardin, May 29 2012

Keywords

Comments

Row 5 of A212868.

Examples

			Some solutions for n=8
..3....5....2....2....4....2....4....2....4....5....5....5....2....6....2....4
..3....5....2....2....6....3....4....5....5....6....6....8....2....6....2....7
..4....5....2....3....6....5....6....5....5....6....6....8....2....6....3....7
..6....5....2....5....6....6....6....5....5....7....8....8....2....7....4....8
..6....8....3....7....7....7....7....6....7....7....8....8....7....8....8....8
		

A212873 Number of nondecreasing sequences of 6 1..n integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 0, 2, 9, 32, 82, 199, 407, 796, 1424, 2407, 3948, 6166, 9456, 14171, 20556, 29007, 40714, 55528, 75323, 100720, 132454, 171336, 221156, 281727, 355410, 445061, 553660, 680365, 835511, 1013730, 1226556, 1475591, 1764220, 2101833, 2493659
Offset: 1

Views

Author

R. H. Hardin May 29 2012

Keywords

Comments

Row 6 of A212868

Examples

			Some solutions for n=8
..3....4....4....2....2....4....3....2....2....4....4....3....2....2....3....5
..3....4....6....2....2....6....3....3....4....4....4....4....2....3....4....5
..4....6....6....2....4....7....6....5....5....4....4....4....5....4....5....5
..4....7....6....3....5....8....6....5....6....4....4....6....6....6....5....5
..4....8....6....8....6....8....8....8....7....4....5....6....6....7....6....6
..5....8....6....8....8....8....8....8....7....6....8....6....8....7....6....7
		

A212874 Number of nondecreasing sequences of 7 1..n integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 0, 2, 12, 40, 122, 319, 722, 1503, 2872, 5159, 9087, 15030, 24441, 38349, 58701, 86682, 127439, 180934, 255292, 354781, 484863, 649910, 870659, 1146208, 1495708, 1935479, 2485685, 3146345, 3979502, 4964688, 6177498, 7637218, 9375304
Offset: 1

Views

Author

R. H. Hardin May 29 2012

Keywords

Comments

Row 7 of A212868

Examples

			Some solutions for n=8
..2....4....2....3....3....2....2....2....3....2....2....2....3....2....3....2
..3....5....3....7....4....3....3....2....4....3....2....4....3....2....3....2
..4....6....4....7....4....5....3....5....4....4....3....4....6....3....4....2
..4....6....6....7....5....7....3....5....6....4....4....6....7....3....7....5
..4....7....6....7....5....8....3....5....8....4....4....7....8....3....7....6
..4....7....8....7....6....8....3....6....8....6....6....8....8....4....7....6
..4....8....8....8....7....8....6....6....8....6....8....8....8....6....7....6
		

A212869 Number of nondecreasing sequences of n 1..n+1 integers with no element dividing the sequence sum.

Original entry on oeis.org

0, 1, 3, 15, 52, 199, 722, 2693, 10052, 37344, 141943, 528323, 2020746, 7720299, 29535575, 112041465, 434810382, 1666519344, 6447232492, 24895996003, 96654652273
Offset: 1

Views

Author

R. H. Hardin May 29 2012

Keywords

Comments

Superdiagonal 1 of A212868

Examples

			All solutions for n=4
..2....4....3....3....3....2....2....3....3....2....2....4....4....2....2
..2....5....3....3....3....2....2....4....3....5....3....4....4....3....3
..4....5....4....3....5....3....2....5....3....5....4....5....4....3....3
..5....5....4....5....5....4....5....5....4....5....4....5....5....5....3
		
Showing 1-10 of 10 results.