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A036491 Transformation of A036490: 5^a*7^b*11^c -> 5^a*7^floor((b+2)/2)*11^c. 3
5, 7, 11, 25, 35, 49, 55, 77, 121, 125, 175, 245, 275, 49, 385, 539, 605, 625, 847, 875, 1225, 1331, 1375, 245, 1925, 343, 2695, 3025, 3125, 539, 4235, 4375, 5929, 6125, 6655, 6875, 1225, 9317, 9625, 1715, 13475, 14641, 15125, 15625, 343, 2695, 21175 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

G. E. Andrews, The Theory of Partitions, Addison-Wesley, 1976, p. 160.

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

MATHEMATICA

f[pp_(*primes*), max_(*maximum term*)] := Module[{a, aa, k, iter}, k = Length[pp]; aa = Array[a, k]; iter = Table[{a[j], 0, PowerExpand @ Log[pp[[j]], max/Times @@ (Take[pp, j-1]^Take[aa, j-1])]}, {j, 1, k}]; Table[Times @@ (pp^aa), Sequence @@ iter // Evaluate] // Flatten // Sort]; A036490 = f[{5, 7, 11}, 2*10^14] // Rest; a[n_] := (a0 = A036490[[n]]; b = Max[1, IntegerExponent[a0, 7]]; 7^(Floor[(b+2)/2]-b) * a0); Table[a[n], {n, 1, Length[A036490]}]; (* Jean-François Alcover, Sep 19 2012, updated Nov 12 2016 *)

PROG

(Haskell)

a036491 n = f z z where

   f x y | x `mod` 2401 == 0 = f (x `div` 49) (y `div` 7)

         | x `mod` 343 == 0  = y `div` 7

         | otherwise         = y

   z = a036490 n

-- Reinhard Zumkeller, Feb 19 2013

CROSSREFS

Cf. A036490, A036492.

Sequence in context: A249735 A218394 A067289 * A036490 A106330 A057247

Adjacent sequences:  A036488 A036489 A036490 * A036492 A036493 A036494

KEYWORD

nonn,easy,look

AUTHOR

Olivier Gérard

EXTENSIONS

Offset corrected by Reinhard Zumkeller, Feb 19 2013

STATUS

approved

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Last modified March 26 00:45 EDT 2019. Contains 321479 sequences. (Running on oeis4.)