A045807 - OEIS

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A045807

7-ish numbers (end in 53, 71, 79, 97).

53, 71, 79, 97, 153, 171, 179, 197, 253, 271, 279, 297, 353, 371, 379, 397, 453, 471, 479, 497, 553, 571, 579, 597, 653, 671, 679, 697, 753, 771, 779, 797, 853, 871, 879, 897, 953, 971, 979, 997, 1053, 1071, 1079, 1097, 1153, 1171, 1179, 1197, 1253, 1271

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

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

FORMULA

Empirical G.f.: x*(53+18*x+8*x^2+18*x^3+3*x^4)/(1-x-x^4+x^5). [Colin Barker, Jan 23 2012]

PROG

(Haskell)

import Data.List (findIndices)

a045807 n = a045807_list !! (n-1)

a045807_list = findIndices (`elem` [53, 71, 79, 97]) $ cycle [0..99]