login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A111614 First upper diagonal of array in A109626. 1
1, 1, 1, 3, 1, 6, 1, 7, 1, 3, 1, 6, 1, 3, 12, 3, 1, 6, 1, 11, 18, 3, 1, 24, 1, 3, 1, 8, 1, 21, 1, 11, 20, 20, 23, 16, 1, 22, 34, 21, 1, 14, 1, 22, 24, 26, 1, 2, 1, 43, 6, 26, 1, 33, 17, 46, 43, 32, 1, 25, 1, 34, 47, 35, 63, 25, 1, 8, 49, 31, 1, 48, 1, 40, 32, 73, 21, 58, 1, 80, 28, 44, 1, 29 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

a(1) = a(2) = 1 and a(p^e) = 1 for odd primes p and noncomposite exponents e.

a(81) = 28 and not 1 because 9^2 = 81.

LINKS

Table of n, a(n) for n=1..84.

MATHEMATICA

f[n_] := f[n] = Block[{a}, a[0] = 1; a[l_] := a[l] = Block[{k = 1, s = Sum[ a[i]*x^i, {i, 0, l - 1}]}, While[ IntegerQ[ Last[ CoefficientList[ Series[(s + k*x^l)^(1/n), {x, 0, l}], x]]] != True, k++ ]; k]; Table[a[j], {j, 0, 128}]]; g[n_, m_] := f[n][[m]]; Table[ g[n, n + 1], {n, 84}]

CROSSREFS

Cf. A109626.

Sequence in context: A040011 A066446 A069625 * A193279 A076889 A134689

Adjacent sequences:  A111611 A111612 A111613 * A111615 A111616 A111617

KEYWORD

nonn

AUTHOR

Paul D. Hanna and Robert G. Wilson v, Jul 30 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 20 19:10 EDT 2021. Contains 343137 sequences. (Running on oeis4.)