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A161700 a(n) = EDP(n,tau(n)) with tau = A000005 and EDP(n,x) = interpolating polynomial for the divisors of n. 31
1, 3, 5, 7, 9, 13, 13, 15, 19, 17, 21, 28, 25, 21, 41, 31, 33, 59, 37, 21, 53, 29, 45, 39, 61, 33, 65, 49, 57, 171, 61, 63, 77, 41, 117, 61, 73, 45, 89, -57, 81, 309, 85, 105, 167, 53, 93, -80, 127, 61, 113, 133, 105, 321, 173, 183, 125, 65, 117, -1039, 121, 69, 155, 127, 201, 333, 133, 189, 149, -69, 141, 117, 145, 81, 317, 217, 269 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

EDP(n,A000005(n) - 1) = n;

EDP(n,1) = A020639(n);

EDP(n,0) = 1;

EDP(n,k) = A027750(A006218(n-1)+k+1), 0<=k < A000005(n).

LINKS

R. Zumkeller, Enumerations of Divisors

Eric Weisstein's World of Mathematics, Divisor

Eric Weisstein's World of Mathematics, Finite Difference

EXAMPLE

n=12: A000005(12)=6;

EDP(12,x) = (x^5 - 5*x^4 + 5*x^3 + 5*x^2 + 114*x + 120)/120 = A161701(x) is the interpolating polynomial for {(0,1),(1,2),(2,3),(3,4),(4,6),(5,12)},

{EDP(12,x): 0<=x<6} = {1, 2, 3, 4, 6, 12} = divisors of 12,

a(12) = EDP(12,6) = 28.

CROSSREFS

A000012, A000027, A005408, A000124, A016813, A086514, A016921, A000125, A058331, A002522, A017281, A161701, A017533, A161702, A161703, A000127, A158057, A161704, A161705, A161706, A161707, A161708, A161709, A161710, A080856, A161711, A161712, A161713, A161714, A161715, A128470, A006261.

Cf. A161856.

Sequence in context: A100432 A145341 A121388 * A063081 A067031 A204454

Adjacent sequences:  A161697 A161698 A161699 * A161701 A161702 A161703

KEYWORD

sign

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 17 2009, Jun 20 2009

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Last modified February 16 20:14 EST 2012. Contains 205962 sequences.