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 1-8 of 8 results.

A125516 Prime numbers that are the sum of three distinct positive squares.

Original entry on oeis.org

29, 41, 53, 59, 61, 83, 89, 101, 107, 109, 113, 131, 137, 139, 149, 157, 173, 179, 181, 197, 211, 227, 229, 233, 241, 251, 257, 269, 277, 281, 283, 293, 307, 313, 317, 331, 337, 347, 349, 353, 373, 379, 389, 397, 401, 409, 419, 421, 433, 443, 449, 457, 461
Offset: 1

Views

Author

Tomas Xordan, Jan 21 2007

Keywords

Examples

			29 = 2^2 + 3^2 + 4^2 = 4 + 9 + 16.
89 = 2^2 + 6^2 + 7^2 = 4 + 36 + 49; also 89 = 3^2 + 4^2 + 8^2 = 9 + 16 + 64.
353 = 2^2 + 5^2 + 18^2 = 4 + 25 + 324; also 353 = 4^2 + 9^2 + 16^2 = 16 + 81 + 256.
		

Crossrefs

Programs

  • Mathematica
    Select[Total/@Subsets[Range[20]^2,{3}],PrimeQ]//Union (* Harvey P. Dale, Aug 12 2025 *)
  • PARI
    {m=22;p=m^2;v=vector(m,x,x^2);w=[];for(i=1,m-2,for(j=i+1,m-1,for(k=j+1,m,if((n=v[i]+v[j]+v[k])
    				

Extensions

Edited, corrected and extended by Klaus Brockhaus, Feb 11 2007

A126658 Prime numbers that are the sum of three distinct positive eighth powers.

Original entry on oeis.org

72353, 1745153, 7444673, 44726593, 49202147, 61503553, 100006817, 100072097, 101686177, 107444417, 143046977, 214756067, 257412163, 430372577, 431661313, 435812033, 447149537, 452523713, 489805633, 530372321, 744340577, 834187553
Offset: 1

Views

Author

Tomas Xordan, Feb 09 2007

Keywords

Comments

These are also the sum of three squares and the sum of three fourth powers: 7444673 = 16^2 + 1296^2 + 2401^2 = 4^4 + 36^4 + 49^4 = 256 + 1679616 + 5764801.

Examples

			72353 = 2^8 + 3^8 + 4^8 = 256 + 6561 + 65536.
7444673 = 2^8 + 6^8 + 7^8 = 256 + 1679616 + 5764801.
49202147 = 5^8 + 7^8 + 9^8 = 390625 + 5764801 + 43046721.
		

Crossrefs

Programs

  • PARI
    {m=14;p=m^8;v=vector(m,x,x^8);w=[];for(i=1,m-2,for(j=i+1,m-1, for(k=j+1,m,if((n=v[i]+v[j]+v[k])
    				

Extensions

Edited, corrected and extended by Klaus Brockhaus, Feb 11 2007

A126708 Prime numbers that are the sum of the cubes of three distinct primes with the same final digit.

Original entry on oeis.org

93871, 100043, 159389, 161071, 236627, 240551, 297233, 325693, 409499, 456623, 468551, 524287, 550061, 583981, 614683, 617401, 653491, 705277, 722807, 800171, 968239, 1016839, 1040311, 1129013, 1172261, 1276039, 1317259, 1326277, 1379519
Offset: 1

Views

Author

Tomas Xordan, Feb 11 2007

Keywords

Examples

			93871 = 13^3 + 23^3 + 43^3 = 2197 + 12167 + 79507 is prime and 13, 23, 43 are primes with the same final digit, hence 93871 is a term.
617401 = 43^3 + 53^3 + 73^3 = 79507 + 148877 + 389017 is prime and 43, 53, 73 are primes with the same final digit, hence 617401 is a term.
14391 = 3^3 + 13^3 + 23^3 = 27 + 2197 + 12167 is not prime; although 3, 13, 23 are primes with the same final digit, 14391 is not in the sequence.
		

Crossrefs

Programs

  • PARI
    {m=116; p=m^3; w=[]; forprime(i=1, m-2, r=i%10; forprime(j=i+1, m-1, forprime(k=j+1, m, if(j%10==r&&k%10==r&&(n=i^3+j^3+k^3)
    				

Extensions

Edited, corrected and extended by Klaus Brockhaus, Feb 16 2007

A306214 Numbers that are the sum of fourth powers of three distinct positive integers in arithmetic progression.

Original entry on oeis.org

98, 353, 707, 962, 1568, 2177, 2658, 3107, 4322, 4737, 5648, 7187, 7793, 7938, 9587, 11312, 12657, 13058, 15392, 15938, 17123, 19362, 20657, 23153, 23603, 25088, 28593, 30963, 31202, 32738, 34832, 35747, 40962, 42528, 45233, 45377, 49712, 49763, 54722, 57153, 57267, 61250, 63938, 67667, 69152
Offset: 1

Views

Author

Antonio Roldán, Jan 29 2019

Keywords

Comments

The remainder of a(n) divided by 16 is less than 5. - Jinyuan Wang, Feb 03 2019

Examples

			353 = 2^4 + 3^4 + 4^4, with 3 - 2 = 4 - 3 = 1;
7187 = 1^4 + 5^4 + 9^4, with 5 - 1 = 9 - 5 = 4.
		

Crossrefs

Programs

  • Maple
    N:= 10^5: # for all terms <= N
    Res:= NULL:
    for a from 1 to floor((N/3)^(1/4)) do
      for d from 1 do
        v:= a^4 + (a+d)^4 + (a+2*d)^4;
        if v > N then break fi;
        Res:= Res, v
      od
    od:
    sort(convert({Res},list)); # Robert Israel, Feb 17 2019
  • PARI
    for(n=1, 70000, k=(n/3)^(1/4); a=2; v=0; while(a<=k&&v==0, d=sqrt(sqrt(2*n+30*a^4)/2-3*a^2); if(d==truncate(d)&&d>=1&&d<=a-1, v=1; print1(n,", ")); a+=1))

A126112 Prime numbers p such that p^4 + (p-1)^4 + (p+1)^4 is a prime number.

Original entry on oeis.org

3, 7, 11, 29, 31, 53, 59, 83, 109, 127, 283, 349, 461, 521, 599, 643, 683, 787, 809, 829, 907, 911, 937, 983, 1093, 1117, 1201, 1289, 1301, 1487, 1523, 1613, 1721, 1877, 2017, 2153, 2267, 2281, 2423, 2521, 2579, 2657, 2677, 2699, 2731, 2741, 2797, 2887, 2969
Offset: 1

Views

Author

Tomas Xordan, Mar 05 2007

Keywords

Examples

			(3-1)^4 + 3^4 + (3+1)^4 = 2^4 + 3^4 + 4^4 = 16 + 81 + 256 = 353 is prime, hence 3 is a term.
(11-1)^4 + 11^4 + (11+1)^4 = 10^4 + 11^4 + 12^4 = 10000 + 14641 + 20736 = 45377 is prime, hence 11 is a term.
		

Crossrefs

Programs

  • Mathematica
    f[n_]:=PrimeQ[(n-1)^4+n^4+(n+1)^4];lst={};Do[p=Prime[n];If[f[p],AppendTo[lst,p]],{n,7!}];lst (* Vladimir Joseph Stephan Orlovsky, Oct 27 2009 *)
    Select[Prime[Range[500]],PrimeQ[Total[(#+{-1,0,1})^4]]&] (* Harvey P. Dale, Dec 07 2012 *)
  • PARI
    forprime(p=2, 3000, if(isprime(q=(p-1)^4+p^4+(p+1)^4), print1(p, ","))) /* Klaus Brockhaus, Mar 09 2007 */

Extensions

Edited, corrected and extended by Klaus Brockhaus, Mar 09 2007

A126113 Primes p^4 + (p-1)^4 + (p + 1)^4 arising from A126112.

Original entry on oeis.org

353, 7793, 45377, 2131937, 2782097, 23705153, 36393857, 142457633, 423617057, 780627473, 19243704833, 44507912417, 135498076577, 221043906737, 386218778417, 512825188193, 652841559233, 1150861306913, 1285043991857
Offset: 1

Views

Author

Tomas Xordan, Mar 05 2007

Keywords

Examples

			A126112(1) = 3 and (3-1)^4+3^4+(3+1)^4 = 2^4+3^4+4^4 = 16+81+256 = 353 is prime, hence a(1) = 353.
A126112(3) = 11 and (11-1)^4+11^4+(11+1)^4 = 10^4+11^4+12^4 = 10000 + 14641 + 20736 = 45377 is prime, hence a(3) = 45377.
		

Crossrefs

Programs

  • PARI
    {forprime(p=2,810,if(isprime(q=(p-1)^4+p^4+(p+1)^4),print1(q,",")))} /* Klaus Brockhaus, Mar 27 2007 */

Extensions

Edited and corrected by Klaus Brockhaus, Mar 27 2007

A126704 Prime numbers that are the sum of three distinct positive sixth powers.

Original entry on oeis.org

4889, 50753, 51481, 66377, 262937, 308801, 797681, 840241, 1000793, 1046657, 1772291, 2303003, 2986777, 3032641, 3107729, 3365777, 4757609, 4804201, 5135609, 7530329, 7534361, 8061041, 8065073, 10516249, 12394721, 14638753
Offset: 1

Views

Author

Tomas Xordan, Feb 11 2007

Keywords

Examples

			4889 = 2^6 + 3^6 + 4^6 = 64 + 729 + 4096.
66377 = 4^6 + 5^6 + 6^6 = 4096 + 15625 + 46656.
		

Crossrefs

Programs

  • Maple
    N:= 10^10; # to find all terms <= N
    A := {}:
    for a from 1 to iroot(N,6) do
      for b from 1 to a-1 while a^6 + b^6 < N do
        for c from (a+b) mod 2 + 1 to b-1 by 2 do
          r:= a^6 + b^6 + c^6;
          if r > N then break fi;
          if isprime(r) then A:= A union {r} fi;
    od od od:
    sort(convert(A,list)); # Robert Israel, Dec 15 2015
  • Mathematica
    Union[Select[Total/@Subsets[Range[20]^6,{3}],PrimeQ]] (* Harvey P. Dale, Apr 20 2013 *)
  • PARI
    {m=16; p=m^6; w=[]; for(i=1,m-2,for(j=i+1, m-1, for(k=j+1, m, if((n=i^6+j^6+k^6)Klaus Brockhaus, Feb 16 2007 */

Extensions

Edited, corrected and extended by Klaus Brockhaus, Feb 16 2007

A140834 Primes that are the sum of at most four nonzero 4th powers.

Original entry on oeis.org

2, 3, 17, 19, 83, 97, 113, 163, 179, 257, 337, 353, 419, 499, 593, 641, 643, 673, 769, 787, 881, 883, 1153, 1297, 1409, 1459, 1553, 1889, 2003, 2083, 2131, 2417, 2579, 2593, 2609, 2657, 2659, 2689, 2819, 3169, 3217, 3697, 3779, 3889, 3907, 4099, 4129, 4177
Offset: 1

Views

Author

Jonathan Vos Post, Jul 18 2008

Keywords

Comments

This sequence was checked by T. D. Noe, who had supplied the b-list for A004833. A037896 is a subset of {Primes that are the sum of at exactly 2 nonzero 4th powers}, itself a subset of A002645 Quartan primes: primes of the form x^4 + y^4, x>0, y>0.

Crossrefs

Formula

A000040 INTERSECTION A004833. {A133740 = Primes that are the sum of at exactly 4 nonzero 4th powers} UNION {A085318 = Primes that are the sum of at exactly 3 nonzero 4th powers} UNION {A002645 = Primes that are the sum of at exactly 2 nonzero 4th powers}.

Extensions

Missing term 353 inserted by Georg Fischer, May 11 2024
Showing 1-8 of 8 results.