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 12 results. Next

A127874 Prime numbers of the form (x^3)/2+(3x^2)/2+3x+3.

Original entry on oeis.org

19, 71, 269, 379, 683, 883, 4663, 6949, 9883, 12239, 16433, 21491, 45631, 66403, 92683, 125119, 186733, 211051, 228383, 256121, 286019, 296479, 352619, 389483, 562589, 578971, 683983, 721619, 842759, 930619, 1150183, 1230391, 1372211
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of degree 3. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Cf. A127873.

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[3 + 3 x + (3 x^2)/2 + x^3/2], AppendTo[a, 3 + 3 x + (3 x^2)/2 + x^3/2]], {x, 1, 300}]; a
    Select[Table[x^3/2+(3x^2)/2+3x+3,{x,150}],PrimeQ] (* Harvey P. Dale, Apr 30 2018 *)

A127876 Integers of the form (x^3)/6 + (x^2)/2 + x + 1.

Original entry on oeis.org

1, 13, 61, 172, 373, 691, 1153, 1786, 2617, 3673, 4981, 6568, 8461, 10687, 13273, 16246, 19633, 23461, 27757, 32548, 37861, 43723, 50161, 57202, 64873, 73201, 82213, 91936, 102397, 113623, 125641, 138478, 152161, 166717, 182173, 198556, 215893, 234211
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of degree 3. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).
Let A be the Hessenberg matrix of order n, defined by: A[1,j]=1, A[i,i]:=3, (i>1), A[i,i-1]=-1, and A[i,j]=0 otherwise. Then, for n>=4, a(n-2)=-coeff(charpoly(A,x),x^(n-3)). - Milan Janjic, Jan 27 2010

Crossrefs

Programs

  • GAP
    Filtered(List([0..150],x->(x^3)/6+(x^2)/2+x+1),IsInt); # Muniru A Asiru, Apr 30 2018
  • Magma
    [(9*n^3-18*n^2+15*n-4)/2: n in [1..30]]; // G. C. Greubel, Apr 29 2018
    
  • Mathematica
    a = {}; Do[If[IntegerQ[1 + x + x^2/2 + x^3/6], AppendTo[a, 1 + x + x^2/2 + x^3/6]], {x, 1, 300}]; a
    Select[Table[x^3/6 + x^2/2 + x + 1, {x, 0, 200}], IntegerQ] (* Harvey P. Dale, Jan 06 2011 *)
  • PARI
    Vec(x*(1+2*x)*(1+7*x+x^2)/(1-x)^4 + O(x^50)) \\ Colin Barker, May 15 2016
    

Formula

From Colin Barker, May 15 2016: (Start)
a(n) = (9*n^3-18*n^2+15*n-4)/2.
a(n) = 4*a(n-1)-6*a(n-2)+4*a(n-3)-a(n-4) for n>4.
G.f.: x*(1+2*x)*(1+7*x+x^2) / (1-x)^4.
(End)
E.g.f.: 2 + (9*x^3 + 9*x^2 + 6*x - 4)*exp(x)/2. - G. C. Greubel, Apr 29 2018

Extensions

a(1) = 1 added by Harvey P. Dale, Jan 06 2011

A127883 a(n) = 60*(n^5/120 + n^4/24 + n^3/6 + n^2/2 + n + 1).

Original entry on oeis.org

163, 436, 1104, 2572, 5485, 10788, 19786, 34204, 56247, 88660, 134788, 198636, 284929, 399172, 547710, 737788, 977611, 1276404, 1644472, 2093260, 2635413, 3284836, 4056754, 4967772, 6035935, 7280788, 8723436, 10386604, 12294697
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 5-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • Magma
    [n^4*(n+5)/2+10*(n^3+3*n^2+6*n+6): n in [1..30]]; // Bruno Berselli, Apr 03 2012
  • Maple
    A127883:=n->60*(n^5/120 + n^4/24 + n^3/6 + n^2/2 + n + 1); seq(A127883(n), n=1..40); # Wesley Ivan Hurt, Mar 27 2014
  • Mathematica
    Table[1/2 (120+x (120+x (60+x (20+x (5+x))))), {x,40}] (* Harvey P. Dale, Mar 12 2011 *)
    CoefficientList[Series[(163 - 542 x + 933 x^2 - 772 x^3 + 338 x^4 - 60 x^5)/(1 - x)^6, {x, 0, 50}], x] (* Vincenzo Librandi, Mar 28 2014 *)

Formula

G.f.: x*(163-542*x+933*x^2-772*x^3+338*x^4-60*x^5)/(1-x)^6. - Colin Barker, Apr 02 2012

A127875 Numbers x for which (x^3)/2+(3x^2)/2+3x+3 is prime.

Original entry on oeis.org

2, 4, 7, 8, 10, 11, 20, 23, 26, 28, 31, 34, 44, 50, 56, 62, 71, 74, 76, 79, 82, 83, 88, 91, 103, 104, 110, 112, 118, 122, 131, 134, 139, 140, 142, 148, 152, 163, 170, 175, 176, 179, 199, 202, 206, 226, 227, 235, 238, 239, 242, 244, 266, 271, 274, 278, 296, 299
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of degree 3. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • Mathematica
    a = {}; Do[If[PrimeQ[3 + 3 x + (3 x^2)/2 + x^3/2], AppendTo[a, x]], {x, 1, 300}]; a

A127878 a(n) = n^4 + 4*n^3 + 12*n^2 + 24*n + 24.

Original entry on oeis.org

24, 65, 168, 393, 824, 1569, 2760, 4553, 7128, 10689, 15464, 21705, 29688, 39713, 52104, 67209, 85400, 107073, 132648, 162569, 197304, 237345, 283208, 335433, 394584, 461249, 536040, 619593, 712568, 815649, 929544, 1054985, 1192728
Offset: 0

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 4-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • GAP
    List([0..40],n->n^4+4*n^3+12*n^2+24*n+24); # Muniru A Asiru, Apr 30 2018
  • Magma
    [n^4 +4*n^3 +12*n^2 +24*n +24: n in [0..30]]; // G. C. Greubel, Apr 29 2018
    
  • Maple
    seq(n^4+4*n^3+12*n^2+24*n+24,n=0..40); # Muniru A Asiru, Apr 30 2018
  • Mathematica
    Table[24 + 24*n + 12*n^2 + 4*n^3 + n^4, {n, 0, 50}]
    LinearRecurrence[{5, -10, 10, -5, 1}, {24, 65, 168, 393, 824}, 50] (* G. C. Greubel, Apr 29 2018 *)
  • PARI
    for(n=0,30, print1(n^4 +4*n^3 +12*n^2 +24*n +24, ", ")) \\ G. C. Greubel, Apr 29 2018
    

Formula

Integral representation in terms of incomplete Gamma function : a(n)= Exp[n]Gamma[5,n], where Gamma[5,n]= Integrate[x^4 Exp[ -x], {x, n, +infinity}]. - N-E. Fahssi, Jan 25 2008
G.f.: (24 -55*x +83*x^2 -37*x^3 +9*x^4)/(1-x)^5. - Colin Barker, Apr 02 2012
E.g.f.: (24 + 41*x + 31*x^2 + 10*x^3 + x^4)*exp(x). - G. C. Greubel, Apr 29 2018

A127882 Primes of the form 60*(x^5/120 + x^4/24 + x^3/6 + x^2/2 + x + 1).

Original entry on oeis.org

163, 977611, 12294697, 37985853397, 49252877161, 137434331779, 830329719061, 1626105882361, 8060524420261, 11467771684597, 13008402510163, 15315610041211, 43633838254429, 71635442712061, 125119099806661
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 5-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • GAP
    Filtered(List([1..2000],x->60*(x^5/120+x^4/24+x^3/6+x^2/2+x+1)),IsPrime); # Muniru A Asiru, Apr 30 2018
  • Maple
    select(isprime,[seq(60*(x^5/120+x^4/24+x^3/6+x^2/2+x+1),x=1..2000)]); # Muniru A Asiru, Apr 30 2018
  • Mathematica
    a = {}; Do[If[PrimeQ[60 + 60*x + 30*x^2 + 10*x^3 + (5*x^4)/2 + x^5/2], AppendTo[a, 60 + 60*x + 30*x^2 + 10*x^3 + (5*x^4)/2 + x^5/2]], {x, 1, 1000}]; a

A127877 Integers of the form (x^4)/24 + (x^3)/6 + (x^2)/2 + x + 1 with x > 0.

Original entry on oeis.org

7, 115, 297, 1237, 2171, 5527, 8221, 16441, 22335, 38731, 49697, 78445, 96787, 142927, 171381, 240817, 282551, 382051, 440665, 577861, 657387, 840775, 945677, 1184617, 1319791, 1624507, 1795281, 2176861, 2388995, 2859391, 3119077, 3691105, 4004967, 4692307
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 4-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • GAP
    Filtered(List([0..150],x->(x^4)/24+(x^3)/6+(x^2)/2+x+1),IsInt); # Muniru A Asiru, Apr 30 2018
  • Magma
    [(11 +5*(-1)^n +16*(2+(-1)^n)*n +18*(3+(-1)^n)*n^2 +36*(1+(-1)^n)*n^3 +54*n^4)/16: n in [1..30]]; // G. C. Greubel, Apr 29 2018
    
  • Mathematica
    a = {}; Do[If[IntegerQ[1 + x + x^2/2 + x^3/6 + x^4/24], AppendTo[a, 1 + x + x^2/2 + x^3/6 + x^4/24]], {x, 1, 100}]; a
    Select[Table[(x^4)/24+(x^3)/6+(x^2)/2+x+1,{x,100}],IntegerQ] (* Harvey P. Dale, Aug 14 2012 *)
  • PARI
    Vec(x*(7+108*x+154*x^2+508*x^3+248*x^4+244*x^5+22*x^6+4*x^7+x^8)/((1-x)^5*(1+x)^4) + O(x^50)) \\ Colin Barker, May 15 2016
    

Formula

From Colin Barker, May 15 2016: (Start)
a(n) = (11 +5*(-1)^n +16*(2+(-1)^n)*n +18*(3+(-1)^n)*n^2 +36*(1+(-1)^n)*n^3 +54*n^4)/16.
a(n) = (27*n^4+36*n^3+36*n^2+24*n+8)/8 for n even.
a(n) = (27*n^4+18*n^2+8*n+3)/8 for n odd.
a(n) = a(n-1)+4*a(n-2)-4*a(n-3)-6*a(n-4)+6*a(n-5)+4*a(n-6)-4*a(n-7)-a(n-8)+a(n-9) for n>9.
G.f.: x*(7+108*x+154*x^2+508*x^3+248*x^4+244*x^5+22*x^6+4*x^7+x^8) / ((1-x)^5*(1+x)^4).
(End)

A127879 Primes of the form x^4 + 4*x^3 + 12*x^2 + 24*x + 24.

Original entry on oeis.org

3760073, 9853769, 117051593, 181145609, 2517933833, 8999750153, 10486376969, 20852229449, 26640445193, 56713997513, 65555973569, 136653695753, 172008443273, 262819256009, 330127243553, 340704528713, 362619554249
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 4-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • GAP
    Filtered(List([1..2000],x->x^4+4*x^3+12*x^2+24*x+24),IsPrime); # Muniru A Asiru, Apr 30 2018
  • Maple
    select(isprime,[seq(x^4+4*x^3+12*x^2+24*x+24,x=1..2000)]); # Muniru A Asiru, Apr 30 2018
  • Mathematica
    a = {}; Do[If[PrimeQ[24 + 24 x + 12 x^2 + 4 x^3 + x^4], AppendTo[a, 24 + 24 x + 12 x^2 + 4 x^3 + x^4]], {x, 1, 1000}]; a
    Select[Table[x^4+4x^3+12x^2+24x+24,{x,780}],PrimeQ[#]&] (* Harvey P. Dale, Jan 24 2013 *)

A127880 Numbers x for which x^4 + 4x^3 + 12x^2 + 24x + 24 is prime.

Original entry on oeis.org

43, 55, 103, 115, 223, 307, 319, 379, 403, 487, 505, 607, 643, 715, 757, 763, 775, 799, 883, 925, 979, 1063, 1069, 1135, 1147, 1165, 1189, 1279, 1309, 1369, 1543, 1567, 1585, 1627, 1693, 1729, 1783, 1813, 1819, 1855, 1903, 1939, 1945, 2083, 2149, 2155
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 4-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • GAP
    Filtered([1..3000],x->IsPrime(x^4+4*x^3+12*x^2+24*x+24)); # Muniru A Asiru, Apr 30 2018
  • Maple
    select(x->isprime(x^4+4*x^3+12*x^2+24*x+24),[$1..3000]); # Muniru A Asiru, Apr 30 2018
  • Mathematica
    a = {}; Do[If[PrimeQ[24 + 24 x + 12 x^2 + 4 x^3 + x^4], AppendTo[a, x]], {x, 1, 1000}]; a
  • PARI
    isok(x) = isprime(x^4 + 4*x^3 + 12*x^2 + 24*x + 24); \\ Michel Marcus, Apr 30 2018
    

A127881 Integers of the form x^5/120 + x^4/24 + x^3/6 + x^2/2 + x + 1 with x > 0.

Original entry on oeis.org

241231, 7057861, 21166951, 52066891, 216295321, 654480151, 1619368381, 2411089396, 3486017011, 6776093041, 12182173471, 20592045301, 26260194241, 33113005531, 51096161161, 76160729191, 110218336621, 131302849486
Offset: 1

Views

Author

Artur Jasinski, Feb 04 2007

Keywords

Comments

Generating polynomial is Schur's polynomial of 5-degree. Schur's polynomials n degree are n-th first term of series expansion of e^x function. All polynomials are non-reducible and belonging to the An alternating Galois transitive group if n is divisible by 4 or to Sn symmetric Galois Group in other case (proof Schur, 1930).

Crossrefs

Programs

  • Mathematica
    a = {}; Do[If[IntegerQ[1 + x + x^2/2 + x^3/6 + x^4/24 + x^5/120], AppendTo[a, 1 + x + x^2/2 + x^3/6 + x^4/24 + x^5/120]], {x, 1, 1000}]; a
    Select[Table[ x^5/120+x^4/24+x^3/6+x^2/2+x+1,{x,450}],IntegerQ] (* Harvey P. Dale, Jan 20 2019 *)
  • PARI
    for(x=1,500,y=x^5+5*x^4+20*x^3+60*x^2+120*x+120;if(y%120==0,print1(y/120, ", "))) \\ Michael B. Porter, Jan 29 2010
    
  • PARI
    isA127881(n)={local(r);r=0;fordiv(120*n-120,x,if(x^5/120+x^4/24+x^3/6+x^2/2+x+1==n,r=1));r} \\ Michael B. Porter, Jan 29 2010
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