
0, 4, 12, 16, 24, 28, 60, 64, 72, 76, 84, 88, 120, 124, 132, 136, 144, 148, 180, 184, 192, 196, 204, 208, 420, 424, 432, 436, 444, 448, 480, 484, 492, 496, 504, 508, 540, 544, 552, 556, 564, 568, 600, 604, 612, 616, 624, 628, 840, 844, 852, 856, 864, 868, 900, 904, 912, 916, 924, 928, 960, 964, 972, 976, 984, 988, 1020, 1024
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OFFSET

1,2


COMMENTS

Numbers for which the prime factor form (A276086) of their primorial base expansion is a square, A000290.


LINKS

Antti Karttunen, Table of n, a(n) for n = 1..9072
Antti Karttunen, Data supplement: n, a(n) computed for n = 1..90720
Index entries for sequences related to primorial base


FORMULA

a(n) = 2*A328770(n).
A000196(A276086(a(n))) = A276086(a(n)/2) = A328834(n).


EXAMPLE

144 is written as "4400" in primorial base (A049345), because 4*A002110(3) + 4*A002110(2) + 0*A002110(1) + 0*A002110(0) = 4*30 + 4*6 = 144, thus all the digits are even and 144 is included in this sequence.


PROG

(PARI)
A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
isA328849(n) = issquare(A276086(n));


CROSSREFS

Cf. A000290, A002110, A010052, A049345, A276086, A276156, A328770.
Cf. A328834, A328850 (squares in this sequence).
Sequence in context: A310568 A257692 A053006 * A261958 A057962 A186303
Adjacent sequences: A328846 A328847 A328848 * A328850 A328851 A328852


KEYWORD

nonn,base


AUTHOR

Antti Karttunen, Oct 30 2019


STATUS

approved

