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 1-9 of 9 results.

A298223 The first of three consecutive primes the sum of which is equal to the sum of three consecutive squares.

Original entry on oeis.org

1511, 5923, 6553, 9791, 11003, 14153, 14633, 15121, 22787, 29231, 36473, 61991, 62987, 68111, 89393, 116273, 137633, 167267, 212501, 233279, 292673, 316957, 426401, 455603, 579113, 603719, 717397, 819017, 938953, 1018057, 1022113, 1292737, 1399477, 1510427
Offset: 1

Views

Author

Colin Barker, Jan 15 2018

Keywords

Examples

			1511 is in the sequence because 1511+1523+1531 (consecutive primes) = 4565 = 1444+1521+1600 (consecutive squares).
		

Crossrefs

Programs

  • PARI
    L=List(); forprime(p=2, 400000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(12*t-24, &sq) && (sq-6)%6==0, u=(sq-6)\6; listput(L, p))); Vec(L)

A298250 The first of three consecutive pentagonal numbers the sum of which is equal to the sum of three consecutive primes.

Original entry on oeis.org

176, 35497, 45850, 68587, 87725, 229126, 488776, 705551, 827702, 1085876, 1127100, 1255380, 1732900, 1914785, 1972840, 2453122, 2737126, 2749297, 2818776, 3245026, 4598126, 5116190, 5522882, 6180335, 6658120, 6939126, 6958497, 7088327, 7114437, 7140595
Offset: 1

Views

Author

Colin Barker, Jan 15 2018

Keywords

Examples

			176 is in the sequence because 176+210+247 (consecutive pentagonal numbers) = 633 = 199+211+223 (consecutive primes).
		

Crossrefs

Programs

  • Maple
    N:= 10^8: # to get all terms where the sums <= N
    Res:= NULL:
    mmax:= floor((sqrt(8*N-23)-5)/6):
    M:= [seq(seq(4*i+j,j=2..3),i=0..mmax/4)]:
    M3:= map(m -> 9/2*m^2+15/2*m+6, M):
    for i from 1 to nops(M) do
    m:= M3[i];
      r:= ceil((m-8)/3);
      p1:= prevprime(r+1);
      p2:= nextprime(p1);
      p3:= nextprime(p2);
      while p1+p2+p3 > m do
        p3:= p2; p2:= p1; p1:= prevprime(p1);
      od:
      if p1+p2+p3 = m then
        Res:= Res, M[i]*(3*M[i]-1)/2;
      fi
    od:
    Res; # Robert Israel, Jan 16 2018
  • Mathematica
    Module[{prs3=Total/@Partition[Prime[Range[10^6]],3,1]},Select[ Partition[ PolygonalNumber[ 5,Range[ 5000]],3,1],MemberQ[ prs3,Total[#]]&]][[All,1]] (* Harvey P. Dale, Dec 25 2022 *)
  • PARI
    L=List(); forprime(p=2, 8000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(72*t-207, &sq) && (sq-15)%18==0, u=(sq-15)\18; listput(L, (3*u^2-u)/2))); Vec(L)

A298251 The first of three consecutive primes the sum of which is equal to the sum of three consecutive pentagonal numbers.

Original entry on oeis.org

199, 35951, 46351, 69221, 88427, 230291, 490481, 707573, 829883, 1088419, 1129693, 1258109, 1736101, 1918157, 1976243, 2456939, 2741159, 2753351, 2822881, 3249419, 4603351, 5121713, 5528623, 6186407, 6664429, 6945559, 6964949, 7094839, 7120963, 7147121
Offset: 1

Views

Author

Colin Barker, Jan 15 2018

Keywords

Examples

			199 is in the sequence because 199+211+223 (consecutive primes) = 633 = 176+210+247 (consecutive pentagonal numbers).
		

Crossrefs

Programs

  • Maple
    N:= 10^8: # to get all terms where the sums <= N
    Res:= NULL:
    mmax:= floor((sqrt(8*N-23)-5)/6):
    M3:= map(t->9/2*t^2+15/2*t+6, [seq(seq(4*i+j,j=2..3),i=0..mmax/4)]):
    for m in M3 do
      r:= ceil((m-8)/3);
      p1:= prevprime(r+1);
      p2:= nextprime(p1);
      p3:= nextprime(p2);
      while p1+p2+p3 > m do
        p3:= p2; p2:= p1; p1:= prevprime(p1);
      od:
      if p1+p2+p3 = m then
        Res:= Res, p1
      fi
    od:
    Res; # Robert Israel, Jan 16 2018
  • Mathematica
    Module[{nn=50000,pn},pn=Total/@Partition[PolygonalNumber[5,Range[ Ceiling[ (1+Sqrt[1+24 Prime[nn]])/6]]],3,1];Select[Partition[ Prime[ Range[ nn]],3,1],MemberQ[pn,Total[#]]&]][[All,1]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Dec 12 2020 *)
  • PARI
    L=List(); forprime(p=2, 8000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(72*t-207, &sq) && (sq-15)%18==0, u=(sq-15)\18; listput(L, p))); Vec(L)

A298272 The first of three consecutive hexagonal numbers the sum of which is equal to the sum of three consecutive primes.

Original entry on oeis.org

6, 6216, 7626, 9180, 16836, 19900, 22366, 29646, 76636, 89676, 93096, 114960, 116886, 118828, 322806, 365940, 397386, 422740, 437580, 471906, 499500, 574056, 595686, 626640, 690900, 743590, 984906, 1041846, 1148370, 1209790, 1260078, 1357128, 1450956
Offset: 1

Views

Author

Colin Barker, Jan 16 2018

Keywords

Examples

			6 is in the sequence because 6+15+28 (consecutive hexagonal numbers) = 49 = 13+17+19 (consecutive primes).
		

Crossrefs

Programs

  • Maple
    N:= 100: # to get a(1)..a(100)
    count:= 0:
    mmax:= floor((sqrt(24*N-87)-9)/12):
    for i from 1 while count < N do
      mi:= 2*i;
      m:= 6*mi^2+9*mi+7;
      r:= ceil((m-8)/3);
      p1:= prevprime(r+1);
      p2:= nextprime(p1);
      p3:= nextprime(p2);
      while p1+p2+p3 > m do
        p3:= p2; p2:= p1; p1:= prevprime(p1);
      od:
      if p1+p2+p3 = m then
        count:= count+1;
        A[count]:= mi*(2*mi-1);
      fi
    od:
    seq(A[i], i=1..count); # Robert Israel, Jan 16 2018
  • PARI
    L=List(); forprime(p=2, 2000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(24*t-87, &sq) && (sq-9)%12==0, u=(sq-9)\12; listput(L, u*(2*u-1)))); Vec(L)

A298273 The first of three consecutive primes the sum of which is equal to the sum of three consecutive hexagonal numbers.

Original entry on oeis.org

13, 6427, 7873, 9439, 17203, 20287, 22783, 30133, 77417, 90523, 93949, 115903, 117841, 119797, 324403, 367649, 399163, 424573, 439441, 473839, 501493, 576193, 597859, 628861, 693223, 746023, 987697, 1044733, 1151399, 1212889, 1263247, 1360417, 1454351
Offset: 1

Views

Author

Colin Barker, Jan 16 2018

Keywords

Examples

			13 is in the sequence because 13+17+19 (consecutive primes) = 49 = 6+15+28 (consecutive hexagonal numbers).
		

Crossrefs

Programs

  • Maple
    N:= 100: # to get a(1)..a(100)
    count:= 0:
    mmax:= floor((sqrt(24*N-87)-9)/12):
    for i from 1 while count < N do
      mi:= 2*i;
      m:= 6*mi^2+9*mi+7;
      r:= ceil((m-8)/3);
      p1:= prevprime(r+1);
      p2:= nextprime(p1);
      p3:= nextprime(p2);
      while p1+p2+p3 > m do
        p3:= p2; p2:= p1; p1:= prevprime(p1);
      od:
      if p1+p2+p3 = m then
        count:= count+1;
      A[count]:= p1;
      fi
    od:
    seq(A[i],i=1..count); # Robert Israel, Jan 16 2018
  • PARI
    L=List(); forprime(p=2, 2000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(24*t-87, &sq) && (sq-9)%12==0, u=(sq-9)\12; listput(L, p))); Vec(L)

A298301 The first of three consecutive heptagonal numbers the sum of which is equal to the sum of three consecutive primes.

Original entry on oeis.org

7, 874, 7209, 15484, 16687, 23863, 68641, 98704, 122877, 239785, 373842, 455182, 498852, 523723, 601966, 652036, 769230, 777573, 1003939, 1019844, 1121245, 1189215, 1203049, 1420159, 1484946, 1594804, 1606807, 1687977, 1804975, 2292973, 2533612, 3012363
Offset: 1

Views

Author

Colin Barker, Jan 16 2018

Keywords

Examples

			7 is in the sequence because 7+18+34 (consecutive hexagonal numbers) = 59 = 17+19+23 (consecutive primes).
		

Crossrefs

Programs

  • PARI
    L=List(); forprime(p=2, 2000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(120*t-519, &sq) && (sq-21)%30==0, u=(sq-21)\30; listput(L, (5*u^2-3*u)/2))); Vec(L)

A298302 The first of three consecutive primes the sum of which is equal to the sum of three consecutive heptagonal numbers.

Original entry on oeis.org

17, 967, 7477, 15877, 17093, 24337, 69467, 99689, 123983, 241333, 375773, 457307, 501077, 525983, 604411, 654587, 772001, 780347, 1007099, 1023037, 1124593, 1192651, 1206497, 1423921, 1488797, 1598791, 1610809, 1692071, 1809221, 2297759, 2538623, 3017849
Offset: 1

Views

Author

Colin Barker, Jan 16 2018

Keywords

Examples

			17 is in the sequence because 17+19+23 (consecutive primes) = 59 = 7+18+34 (consecutive hexagonal numbers).
		

Crossrefs

Programs

  • PARI
    L=List(); forprime(p=2, 4000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(120*t-519, &sq) && (sq-21)%30==0, u=(sq-21)\30; listput(L, p))); Vec(L)

A298312 The first of three consecutive octagonal numbers the sum of which is equal to the sum of three consecutive primes.

Original entry on oeis.org

12160, 74576, 158240, 181056, 269400, 371008, 601216, 606600, 848008, 980408, 1242920, 2075008, 3292816, 3680776, 4477408, 4685000, 5627960, 7505008, 8263480, 9289280, 10397408, 10419760, 10735208, 10757920, 12726680, 13000008, 14200576, 15426936, 15700256
Offset: 1

Views

Author

Colin Barker, Jan 17 2018

Keywords

Examples

			12160 is in the sequence because 12160+12545+12936 (consecutive octagonal numbers) = 37641 = 12541+12547+12553 (consecutive primes).
		

Crossrefs

Programs

  • PARI
    L=List(); forprime(p=2, 20000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(36*t-180, &sq) && (sq-12)%18==0, u=(sq-12)\18; listput(L, 3*u^2-2*u))); Vec(L)
    
  • Python
    from _future_ import division
    from sympy import prevprime, nextprime
    A298312_list, n, m = [], 1, 30
    while len(A298312_list) < 10000:
        k = prevprime(m//3)
        k2 = nextprime(k)
        if prevprime(k) + k + k2 == m or k + k2 + nextprime(k2) == m:
            A298312_list.append(n*(3*n-2))
        n += 1
        m += 18*n + 3 # Chai Wah Wu, Jan 22 2018

A298313 The first of three consecutive primes the sum of which is equal to the sum of three consecutive octagonal numbers.

Original entry on oeis.org

12541, 75521, 159617, 182519, 271181, 373091, 603901, 609289, 851197, 983819, 1246757, 2079997, 3299081, 3687421, 4484737, 4692497, 5636171, 7514477, 8273437, 9299831, 10408577, 10430921, 10746557, 10769281, 12739037, 13012487, 14213621, 15440531, 15713959
Offset: 1

Views

Author

Colin Barker, Jan 17 2018

Keywords

Examples

			12541 is in the sequence because 12541+12547+12553 (consecutive primes) = 37641 = 12160+12545+12936 (consecutive octagonal numbers).
		

Crossrefs

Programs

  • Mathematica
    Module[{nn=5000,oct3},oct3=Total/@Partition[PolygonalNumber[8,Range[nn]],3,1];Select[ Partition[Prime[Range[PrimePi[Ceiling[Max[oct3]/3]]]],3,1],MemberQ[ oct3,Total[ #]]&]][[All,1]] (* Harvey P. Dale, Dec 03 2022 *)
  • PARI
    L=List(); forprime(p=2, 20000000, q=nextprime(p+1); r=nextprime(q+1); t=p+q+r; if(issquare(36*t-180, &sq) && (sq-12)%18==0, u=(sq-12)\18; listput(L, p))); Vec(L)
    
  • Python
    from _future_ import division
    from sympy import prevprime, nextprime
    A298313_list, n, m = [], 1, 30
    while len(A298313_list) < 10000:
        k = prevprime(m//3)
        k2 = prevprime(k)
        k3 = nextprime(k)
        if k2 + k + k3 == m:
            A298313_list.append(k2)
        elif k + k3 + nextprime(k3) == m:
            A298313_list.append(k)
        n += 1
        m += 18*n + 3 # Chai Wah Wu, Jan 22 2018
Showing 1-9 of 9 results.