

A175144


a(n) = d(p(n)1) + d(p(n)+1), where p(n) is the nth prime, and where d(m) is the number of divisors of m.


6



3, 5, 7, 8, 10, 10, 11, 12, 12, 14, 14, 13, 16, 14, 14, 14, 16, 16, 14, 20, 16, 18, 16, 20, 18, 17, 16, 16, 20, 18, 20, 20, 16, 20, 18, 20, 16, 16, 20, 14, 22, 26, 22, 18, 21, 24, 22, 20, 16, 20, 20, 28, 26, 26, 17, 20, 22, 26, 16, 24, 14, 18, 24, 24, 20, 14, 22, 26, 16, 24, 20
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


COMMENTS

If a(n) is a record, then the nth prime is in sequence A090481.


LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000


FORMULA

a(n) = A000005(A006093(n)) + A000005(A008864(n)).  R. J. Mathar, Mar 03 2010


MAPLE

taudiff := proc(n) numtheory[tau](n1)+numtheory[tau](n+1) ; end proc: A175144 := proc(n) taudiff(ithprime(n)) ; end proc: seq(A175144(n), n=1..80) ; # R. J. Mathar, Mar 03 2010


MATHEMATICA

Table[p = Prime[n]; DivisorSigma[0, p  1] + DivisorSigma[0, p + 1], {n, 100}]
Total[DivisorSigma[0, {#1, #+1}]]&/@Prime[Range[80]] (* Harvey P. Dale, Feb 25 2012 *)


CROSSREFS

Cf. A000005, A090481, A090482, A175146.
Sequence in context: A120212 A093670 A185011 * A183054 A188569 A274140
Adjacent sequences: A175141 A175142 A175143 * A175145 A175146 A175147


KEYWORD

nonn


AUTHOR

Leroy Quet, Feb 24 2010


EXTENSIONS

More terms from R. J. Mathar, Mar 03 2010


STATUS

approved



