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A295885 Filter combining sum of proper divisors (A001065) and cototient (A051953) of n. 7
1, 1, 1, 2, 1, 3, 1, 4, 5, 6, 1, 7, 1, 8, 9, 10, 1, 11, 1, 12, 13, 14, 1, 15, 16, 17, 18, 19, 1, 20, 1, 21, 22, 23, 24, 25, 1, 26, 27, 28, 1, 29, 1, 30, 31, 32, 1, 33, 34, 35, 36, 37, 1, 38, 27, 39, 40, 41, 1, 42, 1, 43, 44, 45, 46, 47, 1, 48, 49, 50, 1, 51, 1, 52, 53, 54, 46, 55, 1, 56, 57, 58, 1, 59, 40, 60, 61, 62, 1, 63, 36 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

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

FORMULA

Restricted growth sequence transform of a(n) = (1/2)*(2 + ((A051953(n) + A001065(n))^2) - A051953(n) - 3*A001065(n)).

PROG

(PARI)

allocatemem(2^30);

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; };

write_to_bfile(start_offset, vec, bfilename) = { for(n=1, length(vec), write(bfilename, (n+start_offset)-1, " ", vec[n])); }

A051953(n) = (n-eulerphi(n));

A001065(n) = (sigma(n)-n);

Anotsubmitted5(n) = (1/2)*(2 + ((A051953(n)+A001065(n))^2) - A051953(n) - 3*A001065(n));

write_to_bfile(1, rgs_transform(vector(up_to, n, Anotsubmitted5(n))), "b295885.txt");

CROSSREFS

Cf. A001065, A051953, A291765.

Sequence in context: A299774 A300242 A293892 * A329035 A082904 A034868

Adjacent sequences:  A295882 A295883 A295884 * A295886 A295887 A295888

KEYWORD

nonn

AUTHOR

Antti Karttunen, Dec 03 2017

STATUS

approved

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Last modified February 29 08:26 EST 2020. Contains 332355 sequences. (Running on oeis4.)