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A151960 Sum_{x = A141468(n) to A000040(n)} 1-(-1)^x*x. 0
2, 5, 3, 3, 6, 16, 12, 12, 15, 37, 24, 30, 33, 55, 39, 45, 77, 54, 88, 66, 66, 72, 109, 84, 129, 99, 99, 142, 105, 108, 126, 175, 138, 138, 200, 153, 211, 168, 171, 233, 186, 244, 201, 201, 204, 268, 222, 303, 243, 243, 316, 255, 255, 267, 349, 282 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(1)=1-0+1+1+1-2=2, a(2)=1+1+1-2+1+3=5, a(3)=1-4+1+5=3, a(4)=1-6+1+7=3, a(5)=1-8+1+9+1-10+1+11=6, a(6)=1+9+1-10+1+11+1-12+1+13=16, a(7)=1-10+1+11+1-12+1+13+1-14+1+15+1-16+1+17=12, a(8)=1-12+1+13+1-14+1+15+1-16+1+17+1-18+1+19=12, a(9)=1-14+1+15+1-16+1+17+1-18+1+19+1-20+1+21+1-22+1+23=15, a(10)=1+15+1-16+1+17+1-18+1+19+1-20+1+21+1-22+1+23+1-24+1+25+1-26+1+27+1-28+1+29=37, ...
MATHEMATICA
ZeroAndNonPrime[n_Integer] := FixedPoint[n - 1 + PrimePi@# &, n - 1 + PrimePi@n]; ZeroAndNonPrime[2] = 1; f[n_] := Sum[1-(-1)^x*x, {x, ZeroAndNonPrime@n, Prime@n}]; Array[f, 56]
CROSSREFS
Sequence in context: A162405 A141637 A185581 * A281300 A115320 A073480
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited, corrected and extended by Robert G. Wilson v, Jul 24 2009
Definition clarified by N. J. A. Sloane, Jul 25 2009
Definition corrected by Charles R Greathouse IV, Jul 22 2010
STATUS
approved

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Last modified March 19 06:56 EDT 2024. Contains 370953 sequences. (Running on oeis4.)