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A161669 Sum_{j=k(n)..prime(n)} j where k is the n-th nonprime nonnegative integer. 1
3, 6, 9, 13, 38, 55, 108, 124, 185, 330, 376, 550, 671, 736, 897, 1155, 1470, 1566, 1927, 2178, 2266, 2664, 2958, 3444, 4158, 4521, 4653, 5037, 5215, 5580, 7182, 7656, 8418, 8602, 9999, 10251, 11128, 12040, 12597, 13566, 14570, 14875, 16683, 16951, 17612 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..45.

EXAMPLE

n  k(n)  prime(n)  Sum_{j=k(n)..prime(n)} j

=  ====  ========  ========================

1    0       2               0 + 1 + 2 =  3 = a(1)

2    1       3               1 + 2 + 3 =  6 = a(2)

3    4       5                   4 + 5 =  9 = a(3)

4    6       7                   6 + 7 = 13 = a(4)

5    8      11         8 + 9 + 10 + 11 = 38 = a(5)

PROG

(PARI) k=0; p=2; for(i=1, 1e2, s=p*(p+1)/2-k*(k-1)/2; print1(s", "); p=nextprime(p+1); while(isprime(k++), ))

CROSSREFS

Sequence in context: A316531 A242339 A086838 * A128261 A310162 A310163

Adjacent sequences:  A161666 A161667 A161668 * A161670 A161671 A161672

KEYWORD

nonn,base,easy

AUTHOR

Juri-Stepan Gerasimov, Jun 16 2009, Jun 27 2009

EXTENSIONS

Corrected and extended by Charles R Greathouse IV, Mar 25 2010

Name clarified and Example section edited by Jon E. Schoenfield, Feb 10 2019

STATUS

approved

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Last modified September 21 08:38 EDT 2020. Contains 337268 sequences. (Running on oeis4.)