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

A122140 Numbers m that divide the sum of cubes of the first m primes A098999(m).

Original entry on oeis.org

1, 25, 537, 661, 5199, 113253, 240621, 5337048977, 17434578479, 34216676921, 1991831965911, 4495321247369, 22567781434431, 37328883555791, 110447613624133, 188368390470877, 324587968952249, 1983705516917661
Offset: 1

Views

Author

Alexander Adamchuk, Aug 21 2006

Keywords

Comments

a(19) > 2*10^15. - Paul W. Dyson, Feb 18 2024

Examples

			a(2) = 25 because 25 is the first number n>1 that divides sum of cubes of the first n primes. A098999(25) mod 25 = (2^3 + 3^3 + 5^3 + ... + 89^3 + 97^3) mod 25 = 0.
		

Crossrefs

Cf. A098999.

Programs

  • Mathematica
    s = 0; t = {}; Do[s = s + Prime[n]^3; If[ Mod[s, n] == 0, AppendTo[t, n]], {n, 1000000}]; t

Extensions

a(8) from Donovan Johnson, Oct 15 2012
a(9)-a(10) from Robert Price, Mar 29 2013
a(11) from Paul W. Dyson, Jan 05 2021
a(12) from Bruce Garner, Feb 28 2021
a(13) from Bruce Garner, Apr 06 2021
a(14) from Bruce Garner, May 13 2021
a(15) from Bruce Garner, Jan 08 2022
a(16) from Paul W. Dyson, Jan 17 2022
a(17) from Bruce Garner, Jul 31 2022
a(18) from Paul W. Dyson, Feb 18 2024

A128167 Numbers k such that k divides 1 + Sum_{j=1..k} prime(j)^3 = 1 + A098999(k).

Original entry on oeis.org

1, 2, 4, 5, 6, 10, 12, 14, 55, 82, 87, 935, 973, 1168, 1181, 1457, 5457, 7372, 11250, 17978, 25664, 182717, 472931, 2385026, 3002594, 9249715, 21843515, 37468158, 64403264, 87803374, 140933482, 281907048, 342460116, 1543515106, 1995156064
Offset: 1

Views

Author

Alexander Adamchuk, Feb 22 2007, Feb 23 2007

Keywords

Comments

a(55) > 2.2*10^14. - Bruce Garner, Mar 28 2022

Crossrefs

Cf. A085450 = smallest m > 1 such that m divides Sum_{k=1..m} prime(k)^n.

Programs

  • Mathematica
    k = 0; s = 1; p = 2; lst = {}; While[k < 516862000, s = s + p^3; If[Mod[s, ++k] == 0, AppendTo[lst, k]; Print[{k, p}]]; p = NextPrime@ p]; lst

Extensions

Four more terms from Sean A. Irvine, Jan 19 2011
a(32) & a(33) from Robert G. Wilson v
a(34)-a(35) from Robert Price, Dec 16 2013

A264897 Integers n such that A002110(n) is divisible by A098999(n).

Original entry on oeis.org

138, 163, 873, 1054, 1079, 1604, 1825, 1990, 2079, 2493, 2509, 2810, 2950, 3494, 3800, 3910, 4300, 4462, 4470, 4564, 4593, 4957, 5140, 5450, 5558, 5572, 5581, 5834, 6391, 6792, 6969, 7444, 7892, 8321, 8530, 8581, 9254, 9299, 9522, 9832, 9847, 10082, 10850
Offset: 1

Views

Author

Altug Alkan, Nov 27 2015

Keywords

Comments

A002110(138) has 327 digits.
What is the minimum value of a(n) - a(n-1)?

Crossrefs

Programs

  • Mathematica
    Select[Range@ 10000, Divisible[Product[Prime@ k, {k, #}], Sum[Prime[k]^3, {k, #}]] &] (* Michael De Vlieger, Nov 28 2015 *)
  • PARI
    for(n=1, 11000, if(prod(k=1, n, prime(k)) % sum(k=1, n, prime(k)^3) == 0, print1(n, ", ")))

A122102 a(n) = Sum_{k=1..n} prime(k)^4.

Original entry on oeis.org

16, 97, 722, 3123, 17764, 46325, 129846, 260167, 540008, 1247289, 2170810, 4044971, 6870732, 10289533, 15169214, 23059695, 35177056, 49022897, 69174018, 94585699, 122983940, 161934021, 209392342, 272134583, 360663864, 464724265, 577275146, 708354747, 849512908
Offset: 1

Views

Author

Alexander Adamchuk, Aug 20 2006

Keywords

Comments

a(n) is prime for n = {2,32,90,110,134,152,168,180,194,...} = A122127.

Crossrefs

Partial sums of A030514.

Programs

  • Magma
    [&+[NthPrime(k)^4: k in [1..n]]: n in [1..30]]; // G. C. Greubel, Oct 02 2019
    
  • Maple
    seq(add(ithprime(k)^4, k=1..n), n=1..30); # G. C. Greubel, Oct 02 2019
  • Mathematica
    Table[Sum[Prime[k]^4,{k,1,n}],{n,1,100}]
    Accumulate[Prime[Range[30]]^4] (* Harvey P. Dale, Aug 07 2021 *)
  • PARI
    a(n)=my(s);forprime(p=2,prime(n),s+=p^4); s \\ Charles R Greathouse IV, Aug 02 2013
    
  • Sage
    [sum(nth_prime(k)^4 for k in (1..n)) for n in (1..30)] # G. C. Greubel, Oct 02 2019

Formula

From Vladimir Shevelev, Aug 02 2013: (Start)
a(n) = 0.2*n^5*log(n)^4 + O(n^5*log(n)^3*log(log(n))). The proof is similar to proof for A007504(n) (see link of Shevelev).
A generalization: Sum_{i=1..n} prime(i)^k = 1/(k+1)*n^(k+1)*log(n)^k + O(n^(k+1)*log(n)^(k-1)*log(log(n))).
(End)

A122103 Sum of the fifth powers of the first n primes.

Original entry on oeis.org

32, 275, 3400, 20207, 181258, 552551, 1972408, 4448507, 10884850, 31395999, 60025150, 129369107, 245225308, 392233751, 621578758, 1039774251, 1754698550, 2599294851, 3949419958, 5753649309, 7826720902, 10903777301, 14842817944
Offset: 1

Views

Author

Alexander Adamchuk, Aug 20 2006

Keywords

Comments

a(n) is prime for n = {66, 148, 150, 164, 174, 214, 238, 264, 312, 328, 354, 440, 516, 536, 616, 624, 724, 744, 774, 836, 940, ...} = A122125. Primes of this form are listed in A122126 = {32353461605953, 9874820441996857, 10821208357045699, ...}.

Examples

			a(2) = 275 because the first two primes are 2 and 3, the fifth powers of which are 32 and 243, and 32 + 243 = 275.
a(3) = 3400, because the third prime is 5, its fifth power if 3125 and 275 + 3125 = 3400.
		

Crossrefs

Programs

  • Mathematica
    Table[Sum[Prime[k]^5, {k, n}], {n, 100}]
  • PARI
    a(n)=sum(i=1,n,prime(i)) \\ Charles R Greathouse IV, Nov 30 2013

Formula

a(n) = sum(k = 1 .. n, prime(k)^5).
a(n) = 1/6*n^6*log(n)^5 + O(n^6*log(n)^4*log(log(n))). The proof is similar to proof for A007504(n) (see link of Shevelev). For a generalization, see comment in A122102. - Vladimir Shevelev, Aug 14 2013

A098563 Numbers n such that the sum of the cubes of the first n primes is prime.

Original entry on oeis.org

4, 8, 38, 48, 98, 102, 118, 128, 130, 132, 156, 168, 172, 178, 180, 190, 202, 208, 308, 346, 358, 364, 424, 482, 540, 600, 602, 614, 646, 676, 722, 748, 768, 776, 782, 792, 838, 902, 1016, 1028, 1036, 1058, 1062, 1082, 1086, 1100, 1102, 1132, 1144, 1176
Offset: 1

Views

Author

Rick L. Shepherd, Sep 14 2004

Keywords

Comments

n must clearly be even.

Examples

			4 is a term as the sum of the cubes of the first four primes is 2^3 + 3^3 + 5^3 + 7^3 = 503, which is prime.
		

Crossrefs

Cf. A066525 (corresponding primes), A098561 (sums of squares of primes), A013916 (sums of primes), A098999 (sums of cubes of primes).

Programs

  • Maple
    with(numtheory): P:=proc(n) add(ithprime(k)^3, k=1..n): end:
    A098563 := proc(n)local m: option remember: if(n=0)then return 0: fi: m:=procname(n-1)+2: while true do if(isprime(P(m)))then return m:fi: m:=m+2:od: end:
    seq(A098563(n), n=1..50); # Nathaniel Johnston, Apr 21 2011
  • Mathematica
    Select[Range[1000], PrimeQ[Sum[Prime[i]^3, {i, #}]] &] (* Carl Najafi, Aug 22 2011 *)
  • PARI
    lista(nn) = {s = 0; ip = 0; forprime (p=1, nn, ip++; if (isprime(s+=p^3), print1(ip, ", ")););} \\ Michel Marcus, Aug 22 2015

A122138 Indices k such that A122136(k) is a prime.

Original entry on oeis.org

1, 2, 3, 4, 6, 8, 10, 11, 12, 14, 15, 18, 20, 22, 23, 26, 27, 32, 36, 38, 39, 40, 44, 47, 48, 50, 51, 52, 54, 55, 56, 58, 59, 60, 64, 66, 68, 71, 72, 74, 76, 78, 80, 83, 84, 86, 88, 89, 90, 92, 94, 95, 96, 98, 100, 102, 103, 107, 108, 110, 112, 114, 116, 118, 120, 122, 126
Offset: 1

Views

Author

Alexander Adamchuk, Aug 21 2006

Keywords

Comments

The corresponding primes are listed in A122139.

Crossrefs

Programs

  • Mathematica
    Select[Range[200],PrimeQ[Numerator[Sum[Prime[k]^2,{k,1,#1}]/Product[Prime[k],{k,1,#1}]]]&]

A122142 Numbers m such that m divides sum of 5th powers of the first m primes A122103(m).

Original entry on oeis.org

1, 25, 837, 5129, 94375, 271465, 3576217, 3661659, 484486719, 2012535795, 31455148645, 95748332903, 145967218799, 165153427677, 21465291596581, 97698929023845
Offset: 1

Views

Author

Alexander Adamchuk, Aug 21 2006

Keywords

Comments

No other terms up to 10^8. - Stefan Steinerberger, Jun 06 2007
a(11) > 6*10^9. - Donovan Johnson, Oct 15 2012
a(13) > 10^11. - Robert Price, Mar 30 2013
a(15) > 10^12. - Paul W. Dyson, Jan 04 2021
a(16) > 2.2*10^13. - Bruce Garner, May 09 2021
a(17) > 10^14. - Paul W. Dyson, Feb 04 2022
a(17) > 10^15. - Paul W. Dyson, Nov 19 2024

Examples

			a(2) = 25 because 25 is the first number n>1 that divides A122103[n] = Sum[ Prime[k]^5, {k,1,n} ].
Mod[ A122103[25], 25] = Mod[ 2^5 + 3^5 + 5^5 + ... + 89^5 + 97^5, 25 ] = 0.
		

Crossrefs

Programs

  • Mathematica
    s = 0; t = {}; Do[s = s + Prime[n]^5; If[ Mod[s, n] == 0, AppendTo[t, n]], {n, 1000000}]; t
    Module[{nn = 4*10^6},Select[Thread[{Range[nn], Accumulate[ Prime[ Range[ nn]]^5]}], Divisible[#[[2]], #[[1]]] &]][[All, 1]] (* Generates the first 8 terms; to generate more, increase the value of nn, but the program may take a long time to run. *) (* Harvey P. Dale, Aug 26 2019 *)

Extensions

2 more terms from Stefan Steinerberger, Jun 06 2007
a(9)-a(10) from Donovan Johnson, Oct 15 2012
a(11)-a(12) from Robert Price, Mar 30 2013
a(13)-a(14) from Paul W. Dyson, Jan 04 2021
a(15) from Bruce Garner, May 09 2021
a(16) from Paul W. Dyson, Feb 04 2022

A133548 a(n) = sum of cubes of first n odd primes.

Original entry on oeis.org

27, 152, 495, 1826, 4023, 8936, 15795, 27962, 52351, 82142, 132795, 201716, 281223, 385046, 533923, 739302, 966283, 1267046, 1624957, 2013974, 2507013, 3078800, 3783769, 4696442, 5726743, 6819470, 8044513, 9339542, 10782439, 12830822, 15078913, 17650266
Offset: 1

Views

Author

Artur Jasinski, Sep 16 2007, corrected Jun 08 2008

Keywords

Examples

			a(3)=495 because 3^3+5^3+7^3=495.
		

Crossrefs

Programs

  • Mathematica
    c = 3; a = {}; b = 0; Do[b = b + Prime[n]^c; AppendTo[a, b], {n, 2, 1000}]; a
    Accumulate[Prime[Range[2,40]]^3] (* Harvey P. Dale, Oct 31 2024 *)
  • PARI
    a(n) = sum(i=2, n+1, prime(i)^3); \\ Michel Marcus, Nov 05 2013

Formula

a(n) = A098999(n+1) - 8.

Extensions

More terms from Michel Marcus, Nov 05 2013

A133550 Sum of fifth powers of n odd primes.

Original entry on oeis.org

243, 3368, 20175, 181226, 552519, 1972376, 4448475, 10884818, 31395967, 60025118, 129369075, 245225276, 392233719, 621578726, 1039774219, 1754698518, 2599294819, 3949419926, 5753649277, 7826720870, 10903777269, 14842817912
Offset: 1

Views

Author

Artur Jasinski, Sep 16 2007

Keywords

Examples

			a(2)=3368 because 3^5+5^5 = 3368.
		

Crossrefs

Programs

  • Mathematica
    c = 5; a = {}; b = 0; Do[b = b + Prime[n]^c; AppendTo[a, b], {n, 2, 1000}]; a

Formula

a(n) = A122103(n+1)-32.
Showing 1-10 of 15 results. Next