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A070546 a(n) = Card( k, 0<k<=n such that k is relatively prime to tau(k)=A000005(k)). 1
1, 1, 2, 3, 4, 4, 5, 5, 5, 5, 6, 6, 7, 7, 8, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 31, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

MATHEMATICA

Accumulate[Table[Boole[CoprimeQ[n, DivisorSigma[0, n]]], {n, 1, 100}]] (* Amiram Eldar, Apr 30 2022 *)

PROG

(PARI) for(n=1, 100, print1(sum(i=1, n, if(gcd(i, numdiv(i))-1, 0, 1)), ", "))

CROSSREFS

Partial sums of A322980.

Cf. A000005, A009191, A046642.

Sequence in context: A060197 A116487 A249041 * A034586 A268383 A092338

Adjacent sequences: A070543 A070544 A070545 * A070547 A070548 A070549

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, May 02 2002

STATUS

approved

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Last modified January 29 23:01 EST 2023. Contains 359939 sequences. (Running on oeis4.)