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A247815 Number of primes in n-th row of triangle A077581. 4
0, 1, 1, 3, 2, 5, 3, 5, 5, 7, 4, 9, 5, 9, 7, 10, 6, 14, 7, 13, 10, 13, 8, 18, 10, 14, 11, 16, 9, 26, 10, 17, 14, 18, 13, 26, 11, 20, 16, 23, 12, 31, 13, 22, 21, 22, 14, 32, 15, 28, 20, 27, 15, 35, 19, 29, 22, 28, 16, 45, 17, 29, 27, 30, 21, 44, 18, 32, 26 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(n) = n - A247892(n).

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A000720(A069213(n)) - A001221(n).

PROG

(Haskell)

a247815 = sum . map a010051' . a077581_row

CROSSREFS

Cf. A000720, A001221, A010051, A069213, A077581, A247892.

Sequence in context: A155981 A057958 A225411 * A057953 A129231 A166477

Adjacent sequences:  A247812 A247813 A247814 * A247816 A247817 A247818

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Sep 26 2014

STATUS

approved

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Last modified April 20 03:36 EDT 2019. Contains 322294 sequences. (Running on oeis4.)