A045806 6-ish numbers (end in 23, 27, 61, 89).

23, 27, 61, 89, 123, 127, 161, 189, 223, 227, 261, 289, 323, 327, 361, 389, 423, 427, 461, 489, 523, 527, 561, 589, 623, 627, 661, 689, 723, 727, 761, 789, 823, 827, 861, 889, 923, 927, 961, 989, 1023, 1027, 1061, 1089, 1123, 1127, 1161, 1189, 1223, 1227

Offset

1,1

Links

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

Formula

Empirical G.f.: x*(23+4*x+34*x^2+28*x^3+11*x^4)/(1-x-x^4+x^5). [Colin Barker, Jan 23 2012]

Prog

(Haskell)
import Data.List (findIndices)
a045806 n = a045806_list !! (n-1)
a045806_list = findIndices (`elem` [23, 27, 61, 89]) $ cycle [0..99]
-- Reinhard Zumkeller, Jan 23 2012

Crossrefs

Cf. A045800-A045809.

Cf. A045572, A045797, A045798.

Sequence in context: A282713 A272761 A070774 * A219259 A116224 A127495

Adjacent sequences: A045803 A045804 A045805 * A045807 A045808 A045809

Keyword

nonn,base,easy

Author

J. H. Conway.

Extensions

More terms from Erich Friedman.

Status

approved