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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A293582 Number of compositions of n where each part i is marked with a word of length i over a quinary alphabet whose letters appear in alphabetical order and all five letters occur at least once in the composition.

Original entry on oeis.org

541, 13060, 195020, 2327960, 24418640, 235804122, 2152586500, 18883155160, 160908360260, 1341800118020, 11007289244964, 89168468504160, 715330888641680, 5694960569676240, 45067846839572000, 354959016901129928, 2785141532606257120, 21787375678321712160
Offset: 5

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=5 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(5):
    seq(a(n), n=5..30);
  • Mathematica
    b[n_, k_] := b[n, k] = If[n == 0, 1,
        Sum[b[n - j, k] Binomial[j + k - 1, k - 1], {j, 1, n}]];
    a[n_] := With[{k = 5}, Sum[b[n, k - i] (-1)^i Binomial[k, i], {i, 0, k}]];
    a /@ Range[5, 30] (* Jean-François Alcover, Dec 29 2020, after Alois P. Heinz *)

Formula

a(n) = 30*a(n-1) - 380*a(n-2) + 2690*a(n-3) - 11944*a(n-4) + 35618*a(n-5) - 74912*a(n-6) + 115104*a(n-7) - 132120*a(n-8) + 114500*a(n-9) - 74888*a(n - 10) + 36504*a(n - 11) - 12888*a(n - 12) + 3120*a(n - 13) - 464*a(n - 14) + 32*a(n - 15). - Vaclav Kotesovec, Oct 14 2017
a(n) ~ c * d^n, where d = 7.72502395887257562679242875427350515911685429396536... is the real root of the equation -2 + 10*d - 20*d^2 + 20*d^3 - 10*d^4 + d^5 = 0 and c = 0.67250239588725756267924287542735051591168542939653... is the real root of the equation -1 - 50*c - 1000*c^2 - 10000*c^3 - 50000*c^4 + 100000*c^5 = 0. - Vaclav Kotesovec, Oct 15 2017

A293583 Number of compositions of n where each part i is marked with a word of length i over a senary alphabet whose letters appear in alphabetical order and all six letters occur at least once in the composition.

Original entry on oeis.org

4683, 155928, 3116220, 48697048, 657516672, 8065687344, 92540869002, 1011476639976, 10662168594984, 109327852591208, 1097238662684028, 10827944900524680, 105430826499237004, 1015590292306277376, 9698300806656595584, 91961212434214073824, 866974686508851897168
Offset: 6

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=6 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(6):
    seq(a(n), n=6..30);

Formula

a(n) = 42*a(n-1) - 770*a(n-2) + 8190*a(n-3) - 56854*a(n-4) + 275758*a(n-5) - 980010*a(n-6) + 2645668*a(n-7) - 5576808*a(n-8) + 9366788*a(n-9) - 12715312*a(n - 10) + 14078260*a(n - 11) - 12772248*a(n - 12) + 9499064*a(n - 13) - 5769584*a(n - 14) + 2837496*a(n - 15) - 1113568*a(n - 16) + 340784*a(n - 17) - 78416*a(n - 18) + 12768*a(n - 19) - 1312*a(n - 20) + 64*a(n - 21). - Vaclav Kotesovec, Oct 14 2017

A293584 Number of compositions of n where each part i is marked with a word of length i over a septenary alphabet whose letters appear in alphabetical order and all seven letters occur at least once in the composition.

Original entry on oeis.org

47293, 2075948, 53476920, 1058754564, 17866313444, 270907452704, 3807403790792, 50592275219138, 644225577441572, 7936529529027736, 95254972055989564, 1119634204276346052, 12939870424457764200, 147501747088827091436, 1662420626477581539972
Offset: 7

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=7 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(7):
    seq(a(n), n=7..30);

Formula

a(n) = 56*a(n-1) - 1400*a(n-2) + 20804*a(n-3) - 206864*a(n-4) + 1472576*a(n-5) - 7857468*a(n-6) + 32533654*a(n-7) - 107414264*a(n-8) + 288967984*a(n-9) - 644267912*a(n - 10) + 1206205784*a(n - 11) - 1915352424*a(n - 12) + 2598569764*a(n - 13) - 3027512680*a(n - 14) + 3038439672*a(n - 15) - 2630187744*a(n - 16) + 1962871608*a(n - 17) - 1260043528*a(n - 18) + 692851920*a(n - 19) - 324225312*a(n - 20) + 127932656*a(n - 21) - 42016752*a(n - 22) + 11279872*a(n - 23) - 2411968*a(n - 24) + 395168*a(n - 25) - 46592*a(n - 26) + 3520*a(n - 27) - 128*a(n - 28). - Vaclav Kotesovec, Oct 14 2017

A293585 Number of compositions of n where each part i is marked with a word of length i over an octonary alphabet whose letters appear in alphabetical order and all eight letters occur at least once in the composition.

Original entry on oeis.org

545835, 30532384, 984910128, 24082101504, 496274574936, 9104663637024, 153620123190816, 2434519831873920, 36763980389367378, 534505149483841568, 7538836344403305280, 103747819539055788640, 1399283448432865901624, 18560930972118370361856
Offset: 8

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=8 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(8):
    seq(a(n), n=8..30);

Formula

a(n) = 72*a(n-1) - 2352*a(n-2) + 46452*a(n-3) - 624540*a(n-4) + 6112176*a(n-5) - 45535444*a(n-6) + 266958678*a(n-7) - 1264269754*a(n-8) + 4940034192*a(n-9) - 16203617768*a(n - 10) + 45247660712*a(n - 11) - 108803821608*a(n - 12) + 227386203188*a(n - 13) - 416072786528*a(n - 14) + 670510739364*a(n - 15) - 955987452656*a(n - 16) + 1210032902216*a(n - 17) - 1363000899064*a(n - 18) + 1368396317120*a(n - 19) - 1225293972272*a(n - 20) + 978413136792*a(n - 21) - 696053259552*a(n - 22) + 440365848816*a(n - 23) - 247084003008*a(n - 24) + 122486489680*a(n - 25) - 53377923152*a(n - 26) + 20315614688*a(n - 27) - 6696256832*a(n - 28) + 1890687584*a(n - 29) - 450764768*a(n - 30) + 89006080*a(n - 31) - 14167936*a(n - 32) + 1747264*a(n - 33) - 156672*a(n - 34) + 9088*a(n - 35) - 256*a(n - 36). - Vaclav Kotesovec, Oct 14 2017

A293586 Number of compositions of n where each part i is marked with a word of length i over a nonary alphabet whose letters appear in alphabetical order and all nine letters occur at least once in the composition.

Original entry on oeis.org

7087261, 492006708, 19423259316, 574637640288, 14193955791576, 309660911167464, 6171397007611848, 114853532449557600, 2026594842428425320, 34277110454602760762, 560261324259420037164, 8904738970375872782112, 138290600270036591006520, 2106511986693346884064584
Offset: 9

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=9 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(9):
    seq(a(n), n=9..30);

Formula

a(n) = 90*a(n-1) - 3720*a(n-2) + 94140*a(n-3) - 1642368*a(n-4) + 21111972*a(n-5) - 208936444*a(n-6) + 1643906838*a(n-7) - 10544413816*a(n-8) + 56273496182*a(n-9) - 254124223400*a(n - 10) + 984813733064*a(n - 11) - 3313818868728*a(n - 12) + 9777617820932*a(n - 13) - 25505157099056*a(n - 14) + 59222241227144*a(n - 15) - 123105458091224*a(n - 16) + 230174411303404*a(n - 17) - 388610578141384*a(n - 18) + 594331344450528*a(n - 19) - 825476563250976*a(n - 20) + 1043293124084592*a(n - 21) - 1201650502768408*a(n - 22) + 1262594519234968*a(n - 23) - 1210928179506120*a(n - 24) + 1060266691901408*a(n - 25) - 847323181595664*a(n - 26) + 617639581793392*a(n - 27) - 410205458302944*a(n - 28) + 247843724510640*a(n - 29) - 135949707500048*a(n - 30) + 67526545242016*a(n - 31) - 30273460576096*a(n - 32) + 12201462236512*a(n - 33) - 4399521714368*a(n - 34) + 1410734015840*a(n - 35) - 399326676032*a(n - 36) + 98870585152*a(n - 37) - 21165129088*a(n - 38) + 3859085248*a(n - 39) - 587513600*a(n - 40) + 72658304*a(n - 41) - 7011968*a(n - 42) + 495360*a(n - 43) - 22784*a(n - 44) + 512*a(n - 45). - Vaclav Kotesovec, Oct 14 2017

A293587 Number of compositions of n where each part i is marked with a word of length i over a denary alphabet whose letters appear in alphabetical order and all ten letters occur at least once in the composition.

Original entry on oeis.org

102247563, 8624400680, 408962920820, 14395560938040, 419691762832900, 10733397639516016, 249286917950186760, 5378992003398157520, 109550762660946047540, 2130231901794898870880, 39890088439337327537706, 724087830188007677450600, 12806950694169650253597100
Offset: 10

Views

Author

Alois P. Heinz, Oct 12 2017

Keywords

Crossrefs

Column k=10 of A261781.

Programs

  • Maple
    b:= proc(n, k) option remember; `if`(n=0, 1,
          add(b(n-j, k)*binomial(j+k-1, k-1), j=1..n))
        end:
    a:= n-> (k->add(b(n, k-i)*(-1)^i*binomial(k, i), i=0..k))(10):
    seq(a(n), n=10..30);

Formula

a(n) = 110*a(n-1) - 5610*a(n-2) + 176880*a(n-3) - 3881988*a(n-4) + 63363036*a(n-5) - 803190784*a(n-6) + 8158333238*a(n-7) - 68032529026*a(n-8) + 474993355914*a(n-9) - 2822235496730*a(n - 10) + 14467586756760*a(n - 11) - 64737065451880*a(n - 12) + 255368816478596*a(n - 13) - 895592944790280*a(n - 14) + 2812645592347868*a(n - 15) - 7959012851067608*a(n - 16) + 20400177554223892*a(n - 17) - 47577190249945824*a(n - 18) + 101351234640525316*a(n - 19) - 197858458654518512*a(n - 20) + 354970398396888856*a(n - 21) - 586639546887371480*a(n - 22) + 894863479752319328*a(n - 23) - 1262018115661289704*a(n - 24) + 1647713711756348440*a(n - 25) - 1993736153901444400*a(n - 26) + 2237552288722011272*a(n - 27) - 2330463862262027344*a(n - 28) + 2253297285769248336*a(n - 29) - 2022772844930193632*a(n - 30) + 1685689150486091056*a(n - 31) - 1303653883506384160*a(n - 32) + 935094847660607024*a(n - 33) - 621597594038060528*a(n - 34) + 382531198553819968*a(n - 35) - 217648454420883104*a(n - 36) + 114307777283928640*a(n - 37) - 55307833610580384*a(n - 38) + 24597346495674400*a(n - 39) - 10027630547676256*a(n - 40) + 3735272463460864*a(n - 41) - 1266527133905728*a(n - 42) + 389159192308096*a(n - 43) - 107781232918912*a(n - 44) + 26735152254272*a(n - 45) - 5893548603520*a(n - 46) + 1143628773376*a(n - 47) - 193030560256*a(n - 48) + 27910311552*a(n - 49) - 3387984128*a(n - 50) + 335821568*a(n - 51) - 26104576*a(n - 52) + 1492480*a(n - 53) - 55808*a(n - 54) + 1024*a(n - 55). - Vaclav Kotesovec, Oct 14 2017
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