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 A137576 a(n) = A002326(n) * A006694(n) + 1. 18
 1, 3, 5, 7, 13, 11, 13, 17, 17, 19, 31, 23, 41, 55, 29, 31, 41, 61, 37, 49, 41, 43, 85, 47, 85, 57, 53, 81, 73, 59, 61, 73, 73, 67, 111, 71, 73, 141, 151, 79, 217, 83, 89, 113, 89, 109, 131, 145, 97, 211, 101, 103, 169, 107, 109, 145, 113, 221, 133, 193, 221, 141, 301, 127 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Composite numbers n for which a((n-1)/2)=n are called overpseudoprimes to base 2 (A141232). Theorem. If p and q are odd primes then the equality a((pq-1)/2)=pq is valid if and only if A002326((p-1)/2)=A002326((q-1)/2). Example: A002326(11) = A002326(44). Since 23 and 89 are primes then a((23*89-1)/2)=23*89. A generalization: If p_1

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Last modified August 24 16:39 EDT 2019. Contains 326295 sequences. (Running on oeis4.)