A368993 Doudna-gram for A336547; Partial sums of A368992.

1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 9, 10, 11, 12, 13, 14, 15, 16, 16, 17, 17, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 28, 28, 29, 29, 29, 30, 30, 30, 30, 30, 30, 31, 31, 31, 32, 33, 33, 34, 35, 35, 36, 37, 38, 39, 39, 39, 40, 41, 42, 43, 44, 45, 46, 46, 47, 47, 47, 48, 49, 49, 49, 49, 49, 50, 51, 51, 52, 52, 52

Offset

0,2

Links

Antti Karttunen, Table of n, a(n) for n = 0..65537

Index entries for sequences related to sigma(n)

Formula

a(0) = 0, and for n > 0, a(n) = a(n-1) + A368992(n).

Prog

(PARI)
up_to = 65537;
A005940(n) = { my(p=2, t=1); n--; until(!n\=2, if((n%2), (t*=p), p=nextprime(p+1))); (t); };
A336546(n) = { my(f=factor(n)); (sigma(n)==lcm(vector(#f~, k, sigma(f[k, 1]^f[k, 2])))); };
A368992(n) = A336546(A005940(1+n));
A368993list(up_to) = { my(v=vector(up_to), s=A368992(0)); for(i=1, up_to, s += A368992(i); v[i] = s); (v); };
v368993 = A368993list(up_to);
A368993(n) = if(!n, A368992(0), v368993[n]);

Crossrefs

Partial sums of A368992.

Cf. A005940, A324054, A336546, A336547.

Cf. also A368910, A368991.

Sequence in context: A285762 A185137 A368906 * A137180 A258632 A263283

Adjacent sequences: A368990 A368991 A368992 * A368994 A368995 A368996

Keyword

nonn

Author

Antti Karttunen, Jan 11 2024

Status

approved