A247815 Number of primes in n-th row of triangle A077581.

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

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 A372679 A129231

Adjacent sequences: A247812 A247813 A247814 * A247816 A247817 A247818

Keyword

nonn

Author

Reinhard Zumkeller, Sep 26 2014

Status

approved