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The one and only.

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I think I now have my solution to the June brainteaser in decent shape, with help from some readers.

I note with pleasure that this has got me a mention & link in the Online Encyclopædia of Integer Sequences. This particular entry in the OEIS appeared Thursday-Friday, so I assume I’m its inspiration.

So far as a Derbyshire Function, a Derbyshire Theorem, a Derbyshire Lemma, or even a wretched Derbyshire Conjecture are concerned, “I have been long wakened from that dream of hope” etc. May I at least have a Derbyshire Sequence, please?

The Derbyshire Sequence:  1, 2, 3, 4, 5, 6, 7, 9, 12, 16, 20, 25, 30, 36, 48, 64, 80, 100, 125, 150, 192, 256, 320, 400, 500, 625, 768, 1024, 1280, 1600, 2000, 2500, 3125, 4096, 5120, 6400, 8000, 10000, 12500, 16384, 20480, 25600, 32000, 40000, 50000, 65536, 81920, 102400, 128000, 160000, 200000, 262144, 327680, 409600, 512000, 640000, 800000, 1048576, 1310720, 1638400, 2048000, 2560000, 3200000, 4194304, 5242880, 6553600, 8192000, 10240000, 12800000, 16777216, 20971520, 26214400, 32768000, 40960000, 51200000, 67108864, 83886080, 104857600, 131072000, 163840000, 204800000, 268435456, 335544320, 419430400, 524288000, 655360000, 819200000, 1073741824, 1342177280, 1677721600, 2097152000, 2621440000, 3276800000, 4294967296, 5368709120, 6710886400, 8388608000, 10485760000, 13107200000, 17179869184, …

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