A337202 a(n) = 2*A246277(A047802(n)).

12, 120, 19399380, 195534950863140268380, 1678409980907129617069656971232406858049983380, 1193774258350145889842491509271710921616406416330926349273223856572483463433620

Offset

0,1

Comments

Question: Are there any duplicate terms, not necessarily consecutive? That is, are there two or more terms of A047802 that occur in the same column of array A246278?

Links

Antti Karttunen, Table of n, a(n) for n = 0..13 (Prepared from the b-file of A047802 provided by Jeppe Stig Nielsen)

Index entries for sequences computed from indices in prime factorization

Formula

For all n >= 0, a(n) >= A336389(1+n).

Prog

(PARI)
A246277(n) = if(1==n, 0, my(f = factor(n), k = primepi(f[1, 1])-1); for (i=1, #f~, f[i, 1] = prime(primepi(f[i, 1])-k)); factorback(f)/2);
A337202(n) = 2*A246277(A047802(n));

Crossrefs

Cf. A047802, A246277, A246278, A336389.

Sequence in context: A012442 A262204 A037097 * A299823 A222634 A018204

Adjacent sequences: A337199 A337200 A337201 * A337203 A337204 A337205

Keyword

nonn

Author

Antti Karttunen, Aug 19 2020

Status

approved