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A075764
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Schroeder pseudo-primes: Composite n such that n divides the n-th Schroeder number A001003(n-1).
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0
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105, 261, 301, 693, 1605, 1755, 2151, 2905, 2907, 3393, 3875, 4641, 4833, 5005, 5655, 6279, 6913, 7161, 8883, 9405, 10899, 11025, 11289, 15687, 17199, 19203, 22275, 27387, 36855, 37791, 50007, 50463, 53493, 54891, 55209, 55755, 63327, 64337
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| 105 is a member because A001003(105) = 15646506064359350392347086201481965698808674470977505246623827696393838448345 which is divisible by 105.
105 is a member because A001003(104) = 15646506064359350392347086201481965698808674470977505246623827696393838448345 which is divisible by 105.
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PROG
| (PARI) x1 = 1; x2 = 1; for (n = 3, 100000, x = (3*(2*n - 3)*x1 - (n - 3)*x2)/n; if (!isprime(n), if (!(x%n), print(n))); x2 = x1; x1 = x); (Wasserman)
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CROSSREFS
| Cf. A001003, A013998, A075762.
Sequence in context: A176878 A088595 A146257 * A046299 A010090 A174830
Adjacent sequences: A075761 A075762 A075763 * A075765 A075766 A075767
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KEYWORD
| easy,nonn
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Oct 09 2002
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EXTENSIONS
| More terms from David Wasserman (wasserma(AT)spawar.navy.mil), Feb 23 2005
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