A257233 Multiplicity sequence for the alternating row sums of triangle A257232.

1, 7, 6, 6, 4, 2, 6, 2, 4, 6, 4, 2, 4, 2, 6, 2, 4, 6, 2, 4, 4, 2, 4, 2, 2, 4, 6, 6, 4, 2, 2, 2, 2, 2, 4, 4, 2, 6, 2, 2, 2, 6, 2, 4, 2, 4, 4, 2, 4, 2, 6, 2, 2, 2, 6, 6, 2, 2, 2, 2, 4, 2, 2, 2, 2, 4

Offset: 1

Author

Wolfdieter Lang, Apr 19 2015

Keywords

• nonn
• easy

Comments

The sequence of alternating row sums of A257232 gives one times 1, seven times 2, 6 times 3, six times 4, four times 5, etc., in this order.

Is a(n) = A067970(n-1), n>=3 ? - R. J. Mathar, Apr 24 2015

Crossrefs

Cf. A257232.

Formula

The number m appears a(m) times in the sequence of row sums of triangle A257232 for m = 1, 2, ..., that is in sum(((-1)^(k-1))*(n - (k-1) - [isprime(k)]), k = 1..n) with [isprime(k)] = A010051(k) for n >= 1.