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A177082
a(n) = 2*n*A071148(n).
1
6, 32, 90, 208, 390, 672, 1050, 1568, 2286, 3160, 4290, 5664, 7254, 9128, 11370, 14016, 16966, 20376, 24206, 28400, 33138, 38368, 44206, 50784, 57950, 65624, 73926, 82768, 92278, 103080, 114638, 127104, 140250, 154632, 169750, 185904, 203130, 221312, 240630
OFFSET
1,1
a(n) is the sum of all elements of the n X n matrix M(i,j) = prime(i+1)+prime(j+1).
[For n<= 23, only five matrices (with n=1, n=2, n=3, n=5 and n=7) contain all the even numbers starting from 6 and ending with 2*prime(n+1), the maximum element. If the prime gap prime(n+1)-prime(n) is larger than 2, the even term 2*prime(n+1)-2 is missing in the matrix; the difference equal 2 between prime(n) and prime(n-1) is not a sufficient condition to have a complete set of even numbers in the range 6 .. 2*prime(n+1) in the matrix.]
PROG
(Sage) A177082 = lambda n: 2*n*(sum(primes_first_n(n+1))-2) # D. S. McNeil, Dec 18 2010
(PARI) seq(n)={2*Vec(deriv((Ser(primes(n+1))-2)/(1-x)))} \\ Andrew Howroyd, Jan 14 2020
CROSSREFS
Sequence in context: A121002 A161844 A305291 * A296196 A211918 A288961
KEYWORD
nonn
AUTHOR
Giacomo Fecondo, Dec 09 2010
EXTENSIONS
Terms a(25) and beyond from Andrew Howroyd, Jan 14 2020
STATUS
approved

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Last modified September 20 05:52 EDT 2024. Contains 376020 sequences. (Running on oeis4.)