

A061802


Sum of nth row of triangle of primes: 2; 2 3 2; 2 3 5 3 2; 2 3 5 7 5 3 2; ...; where nth row contains 2n+1 terms.


4



2, 7, 15, 27, 45, 69, 99, 135, 177, 229, 289, 357, 435, 519, 609, 709, 821, 941, 1069, 1207, 1351, 1503, 1665, 1837, 2023, 2221, 2425, 2635, 2851, 3073, 3313, 3571, 3839, 4115, 4403, 4703, 5011, 5331, 5661, 6001, 6353, 6713, 7085, 7469, 7859, 8255, 8665
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OFFSET

0,1


COMMENTS

Row sums of A138143.  Omar E. Pol, Feb 13 2014
For n = 3..9, a(n) = 3*(n^2  3*n + 5).  Nicholas Drozd, Apr 10 2021


LINKS

Harry J. Smith, Table of n, a(n) for n = 0..1000


FORMULA

a(n) = a(n1) + p(n) + p(n1) where p(n) = nth prime.
a(n) = A007504(n) + A007504(n+1) so we have the asymptotic expansion a(n) ~ n^2*log(n).  Henry Bottomley, May 30 2001


PROG

(PARI) { n=1; a=q=0; forprime (p=2, prime(1001), write("b061802.txt", n++, " ", a+=p + q); q=p ) } \\ Harry J. Smith, Jul 28 2009


CROSSREFS

Cf. A001043 (first differences).
Partial sums of A011974.
Sequence in context: A323038 A333637 A113422 * A263603 A003452 A000148
Adjacent sequences: A061799 A061800 A061801 * A061803 A061804 A061805


KEYWORD

nonn,easy


AUTHOR

Amarnath Murthy, May 28 2001


EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 29 2001


STATUS

approved



