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A023522 Sum of exponents in prime-power factorization of p(n)*p(n-1) - 1. 1
1, 2, 2, 3, 2, 4, 3, 3, 4, 2, 3, 3, 2, 4, 4, 3, 3, 4, 4, 2, 4, 4, 3, 5, 4, 3, 5, 5, 3, 5, 3, 4, 2, 4, 3, 5, 4, 4, 6, 4, 3, 3, 3, 4, 3, 4, 5, 4, 4, 3, 3, 3, 4, 4, 5, 4, 4, 3, 5, 2, 3, 5, 3, 4, 6, 3, 4, 3, 3, 4, 3, 5, 8, 3, 4, 6, 8, 3, 6 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Harvey P. Dale, Table of n, a(n) for n = 2..1000

FORMULA

a(n) = A001222(A023515(n)). - Michel Marcus, Sep 30 2013

MATHEMATICA

PrimeOmega[Times@@#-1]&/@Partition[Prime[Range[80]], 2, 1] (* Harvey P. Dale, Nov 22 2014 *)

PROG

(PARI) a(n) = bigomega(prime(n)*prime(n-1) - 1); \\ Michel Marcus, Sep 30 2013

CROSSREFS

Sequence in context: A297113 A086375 A107324 * A205000 A066241 A060025

Adjacent sequences:  A023519 A023520 A023521 * A023523 A023524 A023525

KEYWORD

nonn

AUTHOR

Clark Kimberling

EXTENSIONS

Offset set to 2 and a(1) removed by Michel Marcus, Sep 30 2013

STATUS

approved

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Last modified February 23 03:41 EST 2018. Contains 299473 sequences. (Running on oeis4.)