Occurrences of 2's in A088936.

Terms

a(0) =2a(1) =3a(2) =5a(3) =10a(4) =27a(5) =104a(6) =541a(7) =3498a(8) =26615a(9) =231172a(10) =2250129a(11) =24227486a(12) =285705643a(13) =3660694200a(14) =50624828357a(15) =751426146514