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A328574 a(1) = 0, and then after numbers n whose primorial base expansion doesn't contain any nonleading zeros. 4
0, 1, 3, 5, 9, 11, 15, 17, 21, 23, 27, 29, 39, 41, 45, 47, 51, 53, 57, 59, 69, 71, 75, 77, 81, 83, 87, 89, 99, 101, 105, 107, 111, 113, 117, 119, 129, 131, 135, 137, 141, 143, 147, 149, 159, 161, 165, 167, 171, 173, 177, 179, 189, 191, 195, 197, 201, 203, 207, 209, 249, 251, 255, 257, 261, 263, 267, 269, 279, 281, 285 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

After the initial zero, numbers n for which A276086(n) produces an even number with no gaps in its prime factorization.

Numbers n such that A276086(n) is in A055932; numbers for which A328475(n) is equal to A328572(n) = A003557(A276086(n)).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to primorial base

PROG

(PARI)

A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };

isA055932(n) = { my(f=factor(n)[, 1]~); f==primes(#f); }; \\ From A055932

isA328574(n) = isA055932(A276086(n));

(PARI)

A328475(n) = { my(m=1, p=2, y=1); while(n, if(n%p, m *= p^((n%p)-y), y=0); n = n\p; p = nextprime(1+p)); (m); };

A328572(n) = { my(m=1, p=2); while(n, if(n%p, m *= p^((n%p)-1)); n = n\p; p = nextprime(1+p)); (m); };

isA328574(n) = (A328475(n) == A328572(n));

CROSSREFS

Cf. A003557, A055932, A276086, A328475, A328572.

Positions of 1's in A328573, positions of 0's in A329027, cf. also A328840.

Cf. A227157 for analogous sequence.

Sequence in context: A285519 A047270 A084060 * A227157 A024896 A160771

Adjacent sequences:  A328571 A328572 A328573 * A328575 A328576 A328577

KEYWORD

nonn,base

AUTHOR

Antti Karttunen, Oct 20 2019

EXTENSIONS

Primary definition changed, the old definition moved to comment section by Antti Karttunen, Nov 03 2019

STATUS

approved

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Last modified April 8 04:26 EDT 2020. Contains 333312 sequences. (Running on oeis4.)