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A046022 Primes together with 1 and 4. +0
12
1, 2, 3, 4, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257 (list; graph; listen)
OFFSET

1,2

COMMENT

The values of n which are incrementally largest values of the Smarandache function S(n) seem to produce the same sequence.

Solutions to A000005[x]+A000010[x]-x-1=0. - Labos E. (labos(AT)ana.sote.hu), Aug 23 2001

Also numbers m such that m, phi(m) and tau(m) form an integer triangle, where phi=A000010 is the totient and tau=A000005 the number of divisors (see also A084820). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 04 2003

Terms > 1 are n such that n does not divide (n-1)! - Benoit Cloitre (benoit7848c(AT)orange.fr), Nov 12 2003

Terms > 1 are the sum of their prime factors; 4 (= 2+2) is the only such composite number. - Stuart Orford (sjorford(AT)yahoo.co.uk), Aug 04 2005

A141295(a(n)) = a(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 23 2008

LINKS

Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.

Eric Weisstein's World of Mathematics, Sum of Prime Factors

MATHEMATICA

max = 0; a = {}; Do[m = FactorInteger[n]; w = Sum[m[[k]][[1]]*m[[k]][[2]], {k, 1, Length[m]}]; If[w > max, AppendTo[a, w]; max = w], {n, 1, 1000}]; a - Artur Jasinski (grafix(AT)csl.pl), Apr 06 2008

CROSSREFS

Cf. A002034, A046021.

Sequence in context: A062972 A036844 A033070 this_sequence A073019 A007885 A003037

Adjacent sequences: A046019 A046020 A046021 this_sequence A046023 A046024 A046025

KEYWORD

nonn,easy

AUTHOR

Eric Weisstein (eric(AT)weisstein.com)

EXTENSIONS

Better description from Frank.Ellermann(AT)t-online.de, Jun 15 2001

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Last modified December 2 11:54 EST 2009. Contains 167921 sequences.


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