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A319714 Filter sequence combining the largest proper divisor of n (A032742) with n's residue modulo 4 (A010873). 5
1, 2, 3, 4, 5, 6, 3, 7, 8, 9, 3, 10, 5, 11, 12, 13, 5, 14, 3, 15, 16, 17, 3, 18, 19, 20, 21, 22, 5, 23, 3, 24, 25, 26, 27, 28, 5, 29, 30, 31, 5, 32, 3, 33, 34, 35, 3, 36, 16, 37, 38, 39, 5, 40, 41, 42, 43, 44, 3, 45, 5, 46, 47, 48, 49, 50, 3, 51, 52, 53, 3, 54, 5, 55, 56, 57, 25, 58, 3, 59, 60, 61, 3, 62, 63, 64, 65, 66, 5, 67, 30, 68, 69, 70, 71, 72, 5, 73 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Restricted growth sequence transform of A286474, or equally, of A286473.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..100000

PROG

(PARI)

up_to = 100000;

rgs_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), u=1); for(i=1, length(invec), if(mapisdefined(om, invec[i]), my(pp = mapget(om, invec[i])); outvec[i] = outvec[pp] , mapput(om, invec[i], i); outvec[i] = u; u++ )); outvec; };

A032742(n) = if(1==n, n, n/vecmin(factor(n)[, 1]));

A286474(n) = if(1==n, n, (4*A032742(n) + (n % 4)));

v319714 = rgs_transform(vector(up_to, n, A286474(n)));

A319714(n) = v319714[n];

CROSSREFS

Cf. A010873, A032742, A286473, A286474, A319704.

Sequence in context: A278058 A320115 A319994 * A320004 A319704 A331304

Adjacent sequences:  A319711 A319712 A319713 * A319715 A319716 A319717

KEYWORD

nonn

AUTHOR

Antti Karttunen, Sep 26 2018

STATUS

approved

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Last modified September 28 10:48 EDT 2021. Contains 347714 sequences. (Running on oeis4.)