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A070225 Numbers n such that (sigma(n)-n) - sum(p|n,p^2) = -1. 0
4, 45, 175, 1573, 5491, 26071, 72283, 212341, 367993, 1050703, 1247941, 2608891, 3352351, 5799421, 7040833, 7722991, 11800141, 13766161, 19609831, 22345963, 30273673, 42022741, 73911181, 80434513, 98397223, 141963643, 184867531, 215639401, 235646491, 264196483 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..30.

FORMULA

a(1)=4 a(n+1)=A001359(n)^2*(A001359(n)+2) where A001359(n) are the lesser of twin primes

PROG

(PARI) for(n=1, 1000000, if(sumdiv(n, d, d)-n+1-sumdiv(n, d, isprime(d)*d^2)==0, print1(n, ", ")))

CROSSREFS

Sequence in context: A167781 A173327 A075029 * A132998 A120075 A273832

Adjacent sequences:  A070222 A070223 A070224 * A070226 A070227 A070228

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, May 07 2002

STATUS

approved

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Last modified September 18 17:45 EDT 2019. Contains 327178 sequences. (Running on oeis4.)