factordb · sequences

Sequence

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whole sequence last 20 terms last term range to

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Inverse home prime · Base 28 of 386 length 13 Not fully computed yet - the last known term is composite. ↓ .elf file

Show sequence-development graph

Term size (digits) across the sequence — How the sequence develops - decimal digits of each term vs iteration.

n	Status	Digits	Term	Factorization
0	Fully factored	3	386	2×193
1	Fully factored	4	5406	2×3×17×53
2	Fully factored	7	1176870	2×3×5×39229
3	Fully factored	9	861159014	2×4093×105199
4	Fully factored	11	64661311150<11>	2×5²×41×31542103
5	Fully factored	15	5428512010…98<15>	2×3⁶×197×1889979323<10>
6	Fully factored	23	1999306302…26<23>	2×3×3332177170…21<22>
7	Fully factored	25	2612426901…50<25>	2×3×5³×12619×13009×2121846828…83<14>
8	Fully factored	30	1759755675…38<30>	2×3×1279×82446482981<11>×2781367948…27<15>
9	Fully factored	34	1808476430…26<34>	2×17×127×157×950401×993527×2825166215…63<16>
10	Fully factored	39	4032482632…34<39>	2×41×137×811×4426059336…41<32>
11	Fully factored	44	1672174062…98<44>	2×199×461×1867×4881498578…23<35>
12	Composite	47	1844239917…30<47>	2×5×15307181×1204820089…83<39>
↳	Open Open - the last known term is composite and not yet fully factored.

Open end - submit a factor of the remaining composite (39 digits) of term #12:

120482008920290071144984855142509192483

Check for factors - let the server run a small P-1 / P+1 / ECM step on the composite:

From the command linefdb · curl

fdb

fdb seq view '386' --type 78 --part last20

curl

curl -s 'https://factordb.com:4059/rpc' -H 'Content-Type: application/json' -d '{"jsonrpc":"2.0","id":1,"method":"sequence_view","params":{"start":{"expr":"386"},"type":78,"part":"last20","fr":0}}'