A025571 a(n) = T(3n,n), where T is the array defined in A025564.

1, 3, 19, 140, 1090, 8749, 71604, 593997, 4976785, 42016975, 356879250, 3046096983, 26105109424, 224485080580, 1936029865870, 16738879226139, 145041018993018, 1259189426140919, 10950454909118725, 95374995078513150, 831822673255797630, 7263789225782699928

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Extensions

More terms from Sean A. Irvine, Sep 07 2019