A128496 Row sums of unsigned triangle |A128495|=|S(2;n,m)| (sums of squares of Chebyshev's S-polynomials).

1, 2, 4, 9, 20, 50, 125, 324, 840, 2195, 5736, 15012, 39289, 102854, 269260, 704925, 1845500, 4831574, 12649205, 33116040, 86698896, 226980647, 594243024, 1555748424, 4073002225, 10663258250, 27916772500, 73087059249, 191344405220

Offset: 0

Author

Wolfdieter Lang Apr 04 2007

Keywords

• nonn
• easy

Crossrefs

Cf. A004523 (looks like signed row sums).

Formula

a(n)=sum(|A128495(n,m)|,m=0..n).