A002210

URI: https://gptkb.org/entity/A002210

GPTKB entity

Predicate	Object
gptkbp:instanceOf	integer sequence
gptkbp:author	gptkb:N._J._A._Sloane
gptkbp:citation	gptkb:A001221 gptkb:A007434 gptkb:A008683 A000010 https://oeis.org/A002210
gptkbp:describes	Number of positive integers <= n that are coprime to n.
gptkbp:eighteenth_term	6
gptkbp:eighth_term	4
gptkbp:eleventh_term	10
gptkbp:fifteenth_term	8
gptkbp:fifthBook	4
gptkbp:first_terms	1
gptkbp:form	φ(n) = n * Product_{p\|n} (1 - 1/p), where p runs over the distinct prime divisors of n.
gptkbp:fourteenth_term	6
gptkbp:fourthPlace	2
gptkbp:hasKeyword	easy nonn mult
https://www.w3.org/2000/01/rdf-schema#label	A002210
gptkbp:nineteenth_term	18
gptkbp:ninth_term	6
gptkbp:OEIS	gptkb:A002210
gptkbp:relatedConcept	gptkb:Euler's_totient_function gptkb:Prime_Number coprime
gptkbp:sequence	gptkb:Euler's_totient_function_φ(n) multiplicative number-theoretic
gptkbp:seventeenth_term	16
gptkbp:seventhBook	6
gptkbp:sixteenth_term	8
gptkbp:sixthBook	2
gptkbp:tenth_term	4
gptkbp:thirdPlace	2
gptkbp:thirteenth_term	12
gptkbp:twelfth_term	4
gptkbp:twentieth_term	8
gptkbp:bfsParent	gptkb:Khinchin's_constant
gptkbp:bfsLayer	7