A246260 - OEIS

A246260

a(n) = 1 if A003961(n) is of the form 4k+1, otherwise a(n) = 0, (when A003961(n) is of the form 4k+3). [A003961 is fully multiplicative with a(p) = nextprime(p)].

1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1

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OFFSET

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for characteristic functions

Index entries for sequences computed from indices in prime factorization

FORMULA

a(n) = A000035(A048673(n)).

a(n) = 1 - A000035((A003961(n)-1)/2).

a(n^2) = 1 for all n >= 1. - Antti Karttunen, Apr 08 2022

PROG

(PARI) A246260(n) = { my(f = factor(n)); for (i=1, #f~, f[i, 1] = nextprime(f[i, 1]+1)); (((1+factorback(f))/2)%2); }; \\ Antti Karttunen, Apr 08 2022

(Scheme, two versions)

(define (A246260 n) (A000035 (A048673 n)))

(define (A246260 n) (- 1 (A000035 (/ (- (A003961 n) 1) 2))))

CROSSREFS

Characteristic function of A246261.

Cf. A000035, A003961, A048673, A246262 (partial sums), A246271.

Cf. also A341346.

Sequence in context: A374113 A374107 A373585 * A275973 A218173 A068426

Adjacent sequences: A246257 A246258 A246259 * A246261 A246262 A246263

KEYWORD

nonn

AUTHOR

Antti Karttunen, Aug 21 2014

STATUS

approved