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 1-2 of 2 results.

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

A122125 Indices n such that A122103[n] = Sum[ Prime[k]^5, {k,1,n}] is a prime.

Original entry on oeis.org

66, 148, 150, 164, 174, 214, 238, 264, 312, 328, 354, 440, 516, 536, 616, 624, 724, 744, 774, 836, 940, 1002, 1030, 1034, 1038, 1064, 1086, 1092, 1108, 1162, 1322, 1394, 1424, 1468, 1500, 1630, 1654, 1668, 1684, 1694, 1840, 1886, 1980
Offset: 1

Views

Author

Alexander Adamchuk, Aug 20 2006

Keywords

Comments

Corresponding primes of form Sum[ Prime[k]^5, {k,1,n} ] are listed in A122126[n] = {32353461605953,9874820441996857,10821208357045699,...}.

Crossrefs

Programs

  • Mathematica
    Select[Range[2000],PrimeQ[Sum[Prime[k]^5,{k,1,#1}]]&]
Showing 1-2 of 2 results.