47714domain: NAppears in sequencesNumber of compositions of n such that the first part is 1 and the second differences of the parts are in {-1,0,1}.at n=31A239551One of the two successive approximations up to 7^n for the 7-adic integer sqrt(-3). These are the numbers congruent to 2 mod 7 (except for the initial 0).at n=6A290803