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 15 results. Next

A122207 Primes of the form A109724[n] = A007504[n^2] or the sum of the first n^2 primes.

Original entry on oeis.org

2, 17, 8893, 24133, 768373, 1583293, 2180741, 3875933, 6426919, 173472547, 289093219, 741938801, 2738357903, 2895147163, 3058653607, 17056871941, 24109439269, 26602406177, 29286422621, 62073696299, 65420584637, 68902997299
Offset: 1

Views

Author

Alexander Adamchuk, Aug 25 2006

Keywords

Comments

Numbers n such that A109724[n] = A007504[n^2] is a prime are listed in A122208[n] = {1,2,8,10,22,26,28,32,36,78,88,110,150,152,154,...}.

Examples

			Prime 17 = 2 + 3 + 5 + 7 = a(2) is equal to the sum of the first 4 = 2^2 primes.
Prime 24133 = a(4) is equal to sum of the first 100 = 10^2 primes.
		

Crossrefs

Programs

  • Mathematica
    s=0;Do[s=Sum[Prime[k],{k,1,n^2}];If[PrimeQ[s],Print[{n,n^2,s}]],{n,1,154}]
    Select[Table[Total[Prime[Range[n^2]]],{n,500}],PrimeQ] (* Harvey P. Dale, Jul 20 2024 *)

Formula

a(n) = A109724[ A122208[n] ] = A007504[ A122208[n]^2 ].

Extensions

More terms from Ray Chandler, Dec 02 2018

A122208 Numbers n such that the sum of the first n^2 primes A109724(n) = A007504(n^2) is a prime.

Original entry on oeis.org

1, 2, 8, 10, 22, 26, 28, 32, 36, 78, 88, 110, 150, 152, 154, 232, 252, 258, 264, 316, 320, 324, 368, 376, 426, 496, 516, 532, 608, 644, 666, 686, 764, 828, 832, 880, 932, 958, 1020, 1090, 1096, 1106, 1122, 1156, 1174, 1206, 1264, 1280, 1282, 1290, 1296, 1326
Offset: 1

Views

Author

Alexander Adamchuk, Aug 25 2006

Keywords

Comments

Corresponding primes that are equal to the sum of the first a(n)^2 primes are listed in A122207(n) = {2, 17, 8893, 24133, 768373, 1583293, 2180741, 3875933, 6426919, 173472547, 289093219, 741938801, 2738357903, 2895147163, 3058653607, ...}. - Robert G. Wilson v, Sep 29 2006

Crossrefs

Programs

  • Mathematica
    s = 0; t = {}; Do[s = s + Sum[Prime@k, {k, (n - 1)^2 + 1, n^2}]; If[PrimeQ@s, AppendTo[t, n]], {n, 1341}]; t (* Robert G. Wilson v *)

Formula

A122207(n) = A109724( a(n) ) = A007504( a(n)^2 ). - Robert G. Wilson v, Sep 29 2006

Extensions

More terms from Robert G. Wilson v, Sep 29 2006

A055875 a(0)=1, a(n) = prime(n^3).

Original entry on oeis.org

1, 2, 19, 103, 311, 691, 1321, 2309, 3671, 5519, 7919, 10957, 14753, 19403, 24809, 31319, 38873, 47657, 57559, 69031, 81799, 96137, 112291, 130073, 149717, 171529, 195043, 220861, 248851, 279431, 312583, 347707, 386093, 427169, 470933, 517553
Offset: 0

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Author

Steven Pigeon (pigeon(AT)iro.umontreal.ca), Jul 14 2000

Keywords

Comments

A sequence of increments for Shell sort that produces good results. A bit better than Sedgewick's A036562 and A003462.

Crossrefs

Sequences used for Shell sort: A003462, A033622, A036562, A036564, A036569, A055875.

Programs

  • Magma
    [NthPrime(n^3): n in [0..50] ]; // Vincenzo Librandi, Apr 22 2011
    
  • Mathematica
    {1}~Join~Array[Prime[#^3] &, 35] (* Michael De Vlieger, Apr 13 2021 *)
  • PARI
    first(n) = { my(res = vector(n), t = 0); forprime(p = 2, oo, t++; if(ispower(t, 3, &i), print1([i, p]", "); res[i] = p; if(i >= n, return(concat(1, res))))) } \\ David A. Corneth, Apr 13 2021

Formula

a(n) = A000040(A000578(n)), n>0.

Extensions

More terms from Jonathan Vos Post, Aug 13 2005

A109722 Sum of first 2n primes.

Original entry on oeis.org

0, 5, 17, 41, 77, 129, 197, 281, 381, 501, 639, 791, 963, 1161, 1371, 1593, 1851, 2127, 2427, 2747, 3087, 3447, 3831, 4227, 4661, 5117, 5589, 6081, 6601, 7141, 7699, 8275, 8893, 9523, 10191, 10887, 11599, 12339, 13101, 13887, 14697, 15537, 16401, 17283
Offset: 0

Views

Author

Giovanni Teofilatto, Aug 10 2005

Keywords

Comments

Bisection of A007504.

Crossrefs

Programs

  • Mathematica
    f[n_] := Sum[Prime[k], {k, n}]; Table[f[2n], {n, 0, 43}]
    Join[{0},With[{nn=100},Take[Accumulate[Prime[Range[nn]]],{2,nn,2}]]] (* Harvey P. Dale, Dec 20 2021 *)

Formula

a(n) = A007504(2n).

Extensions

Edited and extended by Ray Chandler, Aug 11 2005

A109723 Sum of the first 2n+1 primes.

Original entry on oeis.org

2, 10, 28, 58, 100, 160, 238, 328, 440, 568, 712, 874, 1060, 1264, 1480, 1720, 1988, 2276, 2584, 2914, 3266, 3638, 4028, 4438, 4888, 5350, 5830, 6338, 6870, 7418, 7982, 8582, 9206, 9854, 10538, 11240, 11966, 12718, 13490, 14288, 15116, 15968, 16840
Offset: 0

Views

Author

Giovanni Teofilatto, Aug 10 2005

Keywords

Comments

Bisection of A007504.

Crossrefs

Programs

  • Mathematica
    f[n_] := Sum[Prime[k], {k, n}]; Table[f[2n + 1], {n, 0, 42}]
    Take[Accumulate[Prime[Range[160]]], {1,160,2}] (* Harvey P. Dale, Jan 11 2011 *)
  • PARI
    a(n) = sum(k=1, 2*n+1, prime(k)); \\ Michel Marcus, Jan 31 2019

Formula

a(n) = A007504(2n+1).

Extensions

Edited and extended by Ray Chandler, Aug 11 2005

A109725 Divide primes in groups with 2n+1 elements and add together.

Original entry on oeis.org

2, 15, 83, 281, 679, 1367, 2461, 4005, 6223, 9017, 12755, 17281, 22967, 29597, 37793, 47229, 57993, 70957, 85343, 101777, 119469, 141079, 163313, 188201, 216203, 247203, 280897, 316551, 355905, 398825, 445509, 494953, 549737, 605711, 665185, 730353, 801481
Offset: 0

Views

Author

Giovanni Teofilatto, Aug 10 2005

Keywords

Comments

First difference of A109724.

Crossrefs

Programs

  • Mathematica
    f[n_] := Sum[Prime[k], {k, n}]; Table[f[(n+1)^2] - f[n^2], {n, 0, 34}]
    With[{nn=40},Total/@TakeList[Prime[Range[nn^2]],Range[1,2nn-1,2]]] (* Requires Mathematica version 11 or later *) (* Harvey P. Dale, Jan 05 2019 *)
  • Python
    from sympy import prime
    def a(n): return sum(prime(i) for i in range(n*n+1, (n+1)**2+1))
    print([a(n) for n in range(37)]) # Michael S. Branicky, Feb 15 2021

Formula

a(n) = A109724(n+1) - A109724(n) = A007504((n+1)^2) - A007504(n^2).

Extensions

Edited and extended by Ray Chandler, Aug 11 2005

A109770 Prime(1^2) + prime(2^2) + ... + prime(n^2).

Original entry on oeis.org

2, 9, 32, 85, 182, 333, 560, 871, 1290, 1831, 2492, 3319, 4328, 5521, 6948, 8567, 10446, 12589, 15026, 17767, 20850, 24311, 28114, 32325, 36962, 42013, 47532, 53539, 60020, 67017, 74590, 82751, 91488, 100829, 110760, 121387, 132708, 144757
Offset: 1

Views

Author

Jonathan Vos Post, Aug 13 2005

Keywords

Examples

			a(1) = 2 = prime(1^2).
a(2) = 9 = 2 + 7 = prime(1^2) + prime(2^2).
a(3) = 32 = 2 + 7 + 23 = prime(1^2) + prime(2^2) + prime(3^2).
a(4) = 32 = 2 + 7 + 23 + 53 = prime(1^2) + prime(2^2) + prime(3^2) prime(4^2).
a(x) = 2+7+23+53+97+151+227+311+419+541+661+827+1009+1193+1427+1619+1879+2143+2437+2741+3083+3461+3803+4211+4637+5051+5519+6007+6481+6997+7573+8161+8737+9341+9931+10627+11321+12049+12743+13499+14327 = 185326.
		

Crossrefs

Programs

  • Mathematica
    Accumulate[Prime[Range[40]^2]] (* Harvey P. Dale, May 31 2014 *)

Formula

Cumulative sum of A011757.

A109791 a(n) = prime(n^4).

Original entry on oeis.org

2, 53, 419, 1619, 4637, 10627, 21391, 38873, 65687, 104729, 159521, 233879, 331943, 459341, 620201, 821641, 1069603, 1370099, 1731659, 2160553, 2667983, 3260137, 3948809, 4742977, 5653807, 6691987, 7867547, 9195889, 10688173, 12358069
Offset: 1

Views

Author

Jonathan Vos Post, Aug 14 2005

Keywords

Comments

Since the prime number theorem is the statement that prime[n] ~ n * log n as n -> infinity [Hardy and Wright, page 10] we have a(n) = prime(n^4) is asymptotically (n^4)*log(n^4) = 4*(n^4)*log(n).

Examples

			a(1) = prime(1^4) = 2,
a(2) = prime(2^4) = 53,
a(3) = prime(3^4) = 419, etc.
		

References

  • G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers. 3rd ed., Oxford Univ. Press, 1954, p. 2.

Crossrefs

Programs

Formula

a(n) = A000040(A000583(n)) for n > 0.

A109789 a(n) = prime(1^3) + prime(2^3) + prime(3^3) + ... + prime(n^3).

Original entry on oeis.org

2, 21, 124, 435, 1126, 2447, 4756, 8427, 13946, 21865, 32822, 47575, 66978, 91787, 123106, 161979, 209636, 267195, 336226, 418025, 514162, 626453, 756526, 906243, 1077772, 1272815, 1493676, 1742527, 2021958, 2334541, 2682248, 3068341
Offset: 1

Views

Author

Jonathan Vos Post, Aug 14 2005

Keywords

Comments

Analogy with prime(1^2) + prime(2^2) + ... + prime(n^2) (A109724). If we take the cumulative sum of A055875 including the 0th value of 1, the 3rd value becomes prime(0^3) + prime(1^3) + prime(2^3) + prime(3^3) = 1 + 2 + 19 + 103 = 125 = 5^3.

Examples

			a(1) = 2 because prime(1^3) = prime(1) = 2;
a(2) = 21 because prime(1^3) + prime(2^3) = prime(1) + prime(8) = 2 + 19;
a(3) = 124 because prime(1^3) + prime(2^3) + prime(3^3) = prime(1) + prime(8) + prime(27) = 2 + 19 + 103;
a(4) = 435 because prime(1^3) + prime(2^3) = prime(1) + prime(8) + prime(27) + prime(64) = 2 + 19 + 103 + 311.
a(6) = 2 + 19 + 103 + 311 + 691 + 1321 = 2447 (which is prime).
a(28) = 2 + 19 + 103 + 311 + 691 + 1321 + 2309 + 3671 + 5519 + 7919 + 10957 + 14753 + 19403 + 24809 + 31319 + 38873 + 47657 + 57559 + 69031 + 81799 + 96137 + 112291 + 130073 + 149717 + 171529 + 195043 + 220861 + 248851 = 1742527 (which is prime).
		

Crossrefs

Programs

  • PARI
    a(n) = sum(k=1, n, prime(k^3)); \\ Michel Marcus, Apr 17 2021

Formula

Cumulative sums of A055875(n) for n>0.

Extensions

Edited by N. J. A. Sloane at the suggestion of Andrew S. Plewe, May 14 2007

A109796 a(n) = prime(1^4) + prime(2^4) + ... + prime(n^4).

Original entry on oeis.org

2, 55, 474, 2093, 6730, 17357, 38748, 77621, 143308, 248037, 407558, 641437, 973380, 1432721, 2052922, 2874563, 3944166, 5314265, 7045924, 9206477, 11874460, 15134597, 19083406, 23826383, 29480190, 36172177, 44039724
Offset: 1

Views

Author

Jonathan Vos Post, Aug 15 2005

Keywords

Comments

Analog of prime(1^2) + prime(2^2) + ... + prime(n^2) (A109724). For a(n) to be prime for n > 1 it is necessary but not sufficient that n == 0 (mod 4).

Examples

			a(1) = 2 because prime(1^4) = prime(1) = 2.
a(2) = 55 because prime(1^4) + prime(2^4) = prime(1) + prime(16) = 2 + 53.
a(3) = 474 because prime(1^4) + prime(2^4) + prime(3^4) = prime(1) + prime(16) + prime(81) = 2 + 53 + 419.
a(4) = 2093 because prime(1^4) + prime(2^4) + prime(3^4) + prime(4^4) = 2 + 53 + 419 + prime(256) = 2 + 53 + 419 + 1619.
a(8) = 2 + 53 + 419 + 1619 + 4637 + 10627 + 21391 + 38873 = 77621 (which is prime).
a(12) = 2 + 53 + 419 + 1619 + 4637 + 10627 + 21391 + 38873 + 65687 + 104729 + 159521 + 233879 = 641437 (which is prime).
a(28) = 2 + 53 + 419 + 1619 + 4637 + 10627 + 21391 + 38873 + 65687 + 104729 + 159521 + 233879 + 331943 + 459341 + 620201 + 821641 + 1069603 + 1370099 + 1731659 + 2160553 + 2667983 + 3260137 + 3948809 + 4742977 + 5653807 + 6691987 + 7867547 + 9195889 = 53235613 (which is prime).
It is a coincidence that a(1), a(2) and a(3) are all palindromes.
		

Crossrefs

First differences are A109791.

Programs

Formula

a(n) = Sum_{i=1..n} A000040(A000583(i)).
Showing 1-10 of 15 results. Next