![Greg Yang on Twitter: "13/ Back to Goodstein sequence: We construct a parallel sequence to the Goodstein sequence as follows: in every hereditary base-k representation, replace k with ω, the first infinite Greg Yang on Twitter: "13/ Back to Goodstein sequence: We construct a parallel sequence to the Goodstein sequence as follows: in every hereditary base-k representation, replace k with ω, the first infinite](https://pbs.twimg.com/media/EhFR3ihXgAEZikQ.png)
Greg Yang on Twitter: "13/ Back to Goodstein sequence: We construct a parallel sequence to the Goodstein sequence as follows: in every hereditary base-k representation, replace k with ω, the first infinite
![Greg Yang on Twitter: "1/ The famous Collatz conjecture asks if repeating the following on any number always ends in 1: if the number is even, half it; if odd, triple it Greg Yang on Twitter: "1/ The famous Collatz conjecture asks if repeating the following on any number always ends in 1: if the number is even, half it; if odd, triple it](https://pbs.twimg.com/media/EhFRL8cXgAIrBjd.png)
Greg Yang on Twitter: "1/ The famous Collatz conjecture asks if repeating the following on any number always ends in 1: if the number is even, half it; if odd, triple it
![R. L. Goodstein. Transfinite ordinals in recursive number theory. The journal of symbolic logic, vol. 12 (1947), pp. 123–129. | The Journal of Symbolic Logic | Cambridge Core R. L. Goodstein. Transfinite ordinals in recursive number theory. The journal of symbolic logic, vol. 12 (1947), pp. 123–129. | The Journal of Symbolic Logic | Cambridge Core](https://static.cambridge.org/content/id/urn%3Acambridge.org%3Aid%3Aarticle%3AS0022481200074557/resource/name/firstPage-S0022481200074557a.jpg)