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 A339547 a(n) is the number of resistance values R=x/y that can be obtained by a network of at most n one-ohm resistors such that a network of more than n one-ohm resistors is needed to obtain the resistance y/x. 0
 15, 172, 1114, 5378, 22321, 83995, 293744, 968965 (list; graph; refs; listen; history; text; internal format)
 OFFSET 10,1 COMMENTS a(n) = 0 for n < 10. REFERENCES Technology Review's Puzzle Corner, How many different resistances can be obtained by combining 10 one ohm resistors? Oct 3, 2003. LINKS Joel Karnofsky, Solution of problem from Technology Review's Puzzle Corner Oct 3, 2003, Feb 23 2004. EXAMPLE a(10) = 15: this is the number of non-reciprocal resistance values provided in Karnofsky's solution of the 10-resistors puzzle. The list of 15 resistances is: 95/106, 101/109, 98/103, 97/98, 103/101, 97/86, 110/91, 103/83, 130/101, 103/80, 115/89, 106/77, 109/77, 98/67, 101/67. a(11) = 172: the corresponding resistances are provided in A338581/A338591. a(12) = 1114: the corresponding resistances are provided in A338582/A338592. CROSSREFS Cf. A180414, A338573, A338601, A338602, A338581, A338591, A338582, A338592. Sequence in context: A058687 A206594 A152586 * A082678 A331516 A107395 Adjacent sequences:  A339544 A339545 A339546 * A339548 A339549 A339550 KEYWORD nonn,hard,more AUTHOR Hugo Pfoertner, Dec 10 2020 STATUS approved

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Last modified November 29 10:22 EST 2021. Contains 349416 sequences. (Running on oeis4.)