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A293226 Restricted growth sequence transform of A293225, a filter combining two products, the other formed from the 1-digits (A293221) and the other from the 2-digits (A293222) present in the ternary expansions of proper divisors of n. 15
1, 2, 2, 3, 2, 4, 2, 5, 6, 7, 2, 8, 2, 9, 10, 11, 2, 12, 2, 13, 14, 15, 2, 16, 4, 17, 18, 19, 2, 20, 2, 21, 22, 23, 24, 25, 2, 26, 27, 28, 2, 29, 2, 30, 31, 32, 2, 33, 34, 35, 12, 36, 2, 37, 38, 39, 40, 41, 2, 42, 2, 43, 44, 45, 46, 47, 2, 48, 49, 50, 2, 51, 2, 52, 53, 54, 55, 56, 2, 57, 58, 59, 2, 60, 61, 62, 63, 64, 2, 65, 66, 67, 68, 69, 70, 71, 2, 72 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

For all i, j: a(i) = a(j) => A001065(i) = A001065(j).

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..19683

PROG

(PARI)

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])); }

A019565(n) = {my(j, v); factorback(Mat(vector(if(n, #n=vecextract(binary(n), "-1..1")), j, [prime(j), n[j]])~))}; \\ This function from M. F. Hasler

A289813(n) = { my (d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==1, 1, 0)), 2); };

A289814(n) = { my (d=digits(n, 3)); fromdigits(vector(#d, i, if (d[i]==2, 1, 0)), 2); };

A293221(n) = { my(m=1); fordiv(n, d, if(d < n, m *= A019565(A289813(d)))); m; };

A293222(n) = { my(m=1); fordiv(n, d, if(d < n, m *= A019565(A289814(d)))); m; };

Anot_submitted(n) = (1/2)*(2 + ((A293222(n) + A293221(n))^2) - A293222(n) - 3*A293221(n)); \\ Eq.class-wise equal to A293225.

write_to_bfile(1, rgs_transform(vector(19683, n, Anot_submitted(n))), "b293226.txt");

CROSSREFS

Cf. A001065, A293221, A293222, A293223, A293224, A293225.

Cf. also A290093, A290094, A293215, A293217, A293232.

Sequence in context: A293217 A329351 A319709 * A328315 A327970 A328767

Adjacent sequences:  A293223 A293224 A293225 * A293227 A293228 A293229

KEYWORD

nonn

AUTHOR

Antti Karttunen, Oct 03 2017

STATUS

approved

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Last modified February 24 09:40 EST 2020. Contains 332209 sequences. (Running on oeis4.)