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A179546
a(n) = p^2*(p + 3)/2, where p = prime(n).
1
10, 27, 100, 245, 847, 1352, 2890, 3971, 6877, 13456, 16337, 27380, 36982, 42527, 55225, 78652, 107911, 119072, 157115, 186517, 202502, 255881, 296227, 364366, 470450, 530452, 562277, 629695, 665336, 740602, 1048385, 1149787, 1313830
OFFSET
1,1
COMMENTS
Old name was "The first a(n) numbers killed in a Sieve of Eratosthenes".
LINKS
FORMULA
p^2*(p+3)/2 as p runs through the primes. [R. J. Mathar, Aug 05 2010]
EXAMPLE
2: 2*2 + 2*3 = 2*(3*4/2-1) = 10;
3: 3*2 + 3*3 + 3*4 = 3*(4*5/2-1) = 27;
5: 5*2 + 5*3 + 5*4 + 5*5 + 5*6 = 5*(6*7/2-1) = 100;
7: 7*2 + 7*3 + 7*4 + 7*5 + 7*6 + 7*7 + 7*8 = 7*(8*9/2-1) = 245; etc.
MATHEMATICA
Table[Prime[n]^2 (Prime[n] + 3)/2, {n, 40}] (* Bruno Berselli, Feb 03 2015 *)
#^2 (#+3)/2&/@Prime[Range[40]] (* Harvey P. Dale, Feb 23 2018 *)
PROG
(PARI) vector(50, n, p=prime(n); p^2*(p+3)/2) \\ Michel Marcus, Feb 03 2015
(Magma) [p^2*(p+3)/2: p in PrimesUpTo(200)]; // Bruno Berselli, Feb 03 2015
CROSSREFS
Cf. A000040.
Sequence in context: A220021 A008468 A267217 * A119548 A219629 A262316
KEYWORD
nonn
AUTHOR
Odimar Fabeny, Jul 19 2010
EXTENSIONS
More terms from R. J. Mathar, Aug 05 2010
Name and example rephrased and offset changed by Editors of the OEIS, Feb 03 2015
STATUS
approved