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A047886 Triangle read by rows: T(n,k) = pi(n+k) - pi(n) - pi(k), where pi() = A000720 (n >= 0, 0 <= k <= n). 7
0, 0, 1, 0, 1, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0, 0, 0, -1, -1, -2, 0, 1, 0, -1, -1, -1, -1, 0, 0, -1, -2, -1, -2, -1, -2, 0, 0, -1, -1, -1, -1, -1, -2, -2, 0, 0, 0, -1, 0, -1, -1, -2, -1, -1, 0, 1, 0, 0, 0, -1, -1, -1, -1, 0, 0, 0, 0, 0, -1, -1, -2, -1, -2, -1, -1, -1, -2, 0, 1, 0, -1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
0,21
COMMENTS
T(n,0)=0; for n > 0: T(n,1)=A010051(n); T(n,n)=-A060208(n). - Reinhard Zumkeller, Apr 15 2008
A212210-A212213 are the preferred versions of this array.
LINKS
EXAMPLE
Triangle begins
0;
0, 1;
0, 1, 0;
0, 0, 0, -1;
0, 1, 0, 0, 0;
0, 0, 0, -1, -1, -2;
...
MATHEMATICA
Flatten[Table[PrimePi[n+k]-PrimePi[n]-PrimePi[k], {n, 0, 20}, {k, 0, n}]] (* Harvey P. Dale, Feb 22 2012 *)
CROSSREFS
Sequence in context: A050370 A050374 A238877 * A239366 A014944 A015879
KEYWORD
sign,easy,tabl
AUTHOR
EXTENSIONS
More terms from James A. Sellers, Dec 22 1999
STATUS
approved

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Last modified March 28 22:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)