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.

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A131348 Sum of squares of prime quadruplets.

Original entry on oeis.org

364, 940, 44140, 152140, 2722540, 8820940, 14062540, 17388940, 42380140, 48024940, 127916140, 356076940, 676520140, 979064140, 990360940, 1032336940, 1302488140, 1431108940, 1509322540, 1766520940, 1984702540, 2561372140
Offset: 1

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Author

Jonathan Vos Post, Sep 29 2007

Keywords

Comments

This is to prime quadruplets A007530 as sums of squares of twin primes A063533 are to twin primes. This is to prime quadruplets A007530 as A133524 is to four consecutive primes. Note that prime quadruplets are not the same as four consecutive primes. After a(1) these are always multiples of 20, because after A007530(1) = 5, all A007530(n) == 1 mod 10. a(n) is a prime times 20 for an = 1, 2, 3, 12, 16, 21.

Examples

			a(1) = 364 = 5^2 + 7^2 + 11^2 + 13^2.
a(2) = 940 = 11^2 + 13^2 + 17^2 + 19^2.
a(3) = 44140 = 101^2 + (103)^2 + (107)^2 + (109)^2 because 101, 103, 107, 109 are a prime quadruplet.
		

Crossrefs

Programs

  • Mathematica
    Total[#^2]&/@Select[Partition[Prime[Range[3000]],4,1],MatchQ[#,{#[[1]],#[[1]]+2,#[[1]]+6,#[[1]]+8}]&]  (* Harvey P. Dale, Feb 03 2011 *)

Formula

a(n) = p^2 + (p+2)^2 + (p+6)^2 + (p+8)^2 for p in A007530.

Extensions

Corrected and extended by Harvey P. Dale, Feb 03 2011
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