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A163631 Partial sums of the odd nonprimes, A014076. 1
1, 10, 25, 46, 71, 98, 131, 166, 205, 250, 299, 350, 405, 462, 525, 590, 659, 734, 811, 892, 977, 1064, 1155, 1248, 1343, 1442, 1547, 1658, 1773, 1890, 2009, 2130, 2253, 2378, 2507, 2640, 2775, 2916, 3059, 3204, 3351, 3504, 3659, 3818, 3979, 4144, 4313 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

All entries besides the first are of the form 2+(k+1)^2-A007504(j), e.g., 10=2+25-17, 25=2+64-41, where the square is the sum of all odd numbers up to 1+2*k, and the 2 and A007504 represent the partial sum over the primes.

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..5000

FORMULA

a(n) = Sum_{x= 1st odd nonprime..n-th odd nonprime}x.

MATHEMATICA

upto=200; Accumulate[Complement[Range[1, upto, 2], Prime[Range[2, PrimePi[upto]]]]] (* Harvey P. Dale, Mar 19 2011 *)

PROG

(PARI) lista(nn) = {my(s = 0); forstep (n=1, nn, 2, if (!isprime(n), s+= n; print1(s, ", ")); ); } \\ Michel Marcus, Aug 01 2017

CROSSREFS

Cf. A014076.

Sequence in context: A269457 A043123 A043903 * A100536 A024838 A020179

Adjacent sequences:  A163628 A163629 A163630 * A163632 A163633 A163634

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Aug 02 2009, Oct 10 2009

EXTENSIONS

150 replaced with 250 by R. J. Mathar, Aug 06 2009

STATUS

approved

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Last modified October 15 07:29 EDT 2018. Contains 316202 sequences. (Running on oeis4.)