Thread: a Little problem

S1: 1
S2: 21
S3: 2221
S4: 7221
what's S5, S6...etc?

Originally Posted by Decoder

S1: 1
S2: 21
S3: 2221
S4: 7221
what's S5, S6...etc?

Without any background S5, and S6.. could be anything. So tell us more
about the origin of the problem.

Alternatively putting a Lagrangian Interpolating Polynomial (http://mathworld.wolfram.com/Lagrang...olynomial.html)
through the points gives S5=15641, and S6=28101.

The Online Encyclopedia of integer sequences knows nothing of this sequence.

RonL

Well, it is not an arithmetic progression.
Not a geometric progression.
And not any exponential.

Of course, S5, S6 can be anything.