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1,1

See A237607 for the numbers themselves and for more comments.

The ratio r(n) = a(n+1)/a(n) seems to converge to a constant value of about 4.245...

Table of n, a(n) for n=1..13.

Stanislav Sykora, PARI/GP scripts for genetic threads

One-digit numbers k with moebius(k)=0 are 4, 8 and 9. Hence a(1) = 3.

(PARI) See the link (use GT_DivMod0 with "IsMoebiusZero" for the "property" argument).

Cf. A237607.

Sequence in context: A006502 A024037 A281349 * A100295 A091701 A242637

Adjacent sequences: A237605 A237606 A237607 * A237609 A237610 A237611

nonn,hard,more,base

Stanislav Sykora, Feb 15 2014

a(12)-a(13) from Lars Blomberg, Jan 02 2016

approved