A324530 - OEIS

A324530

Lexicographically earliest sequence such that a(i) = a(j) => f(i) = f(j), where f(n) = [A033879(n), A318458(n)] for all other numbers, except f(1) = -1.

1, 2, 3, 2, 4, 5, 6, 2, 7, 8, 9, 10, 11, 12, 13, 2, 14, 15, 16, 17, 9, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 2, 16, 28, 19, 29, 30, 31, 19, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 2, 39, 56, 57, 58, 35, 59, 60, 61, 62, 63, 64, 65, 51, 66, 67, 68, 41, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 51, 80

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OFFSET

1,2

LINKS

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

Index entries for sequences related to binary expansion of n

Index entries for sequences related to sigma(n)

FORMULA

a(2^n) = 2 for all n >= 1.

PROG

(PARI)

up_to = 65537;

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; };

A033879(n) = (n+n-sigma(n));

A318458(n) = bitand(n, sigma(n)-n);

Aux324530(n) = if(1==n, -1, [A033879(n), A318458(n)]);

v324530 = rgs_transform(vector(up_to, n, Aux324530(n)));

A324530(n) = v324530[n];

CROSSREFS

Cf. A033879, A318458, A324389, A324400, A324531.

Sequence in context: A336146 A324531 A323897 * A324347 A324346 A323904

Adjacent sequences: A324527 A324528 A324529 * A324531 A324532 A324533

KEYWORD

nonn

AUTHOR

Antti Karttunen, Mar 05 2019

STATUS

approved