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A234431 Numbers that are the sum of 2 successive evil numbers (A001969). 3
3, 8, 11, 15, 19, 22, 27, 32, 35, 38, 43, 47, 51, 56, 59, 63, 67, 70, 75, 79, 83, 88, 91, 94, 99, 104, 107, 111, 115, 118, 123, 128, 131, 134, 139, 143, 147, 152, 155, 158, 163, 168, 171, 175, 179, 182, 187, 191, 195, 200, 203, 207, 211, 214, 219, 224, 227, 230, 235, 239, 243, 248, 251 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

First differences are in {3, 4, 5}; 4*n - 2 <= a(n) <= 4*n. - Charles R Greathouse IV, Dec 26 2013

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A001969(n) + A001969(n + 1).

MATHEMATICA

Total/@Partition[Select[Range[0, 200], EvenQ[DigitCount[#, 2, 1]]&], 2, 1] (* Harvey P. Dale, Nov 02 2015 *)

PROG

(PARI) a(n)=4*n+hammingweight(n-1)%2+hammingweight(n)%2-2 \\ Charles R Greathouse IV, Dec 26 2013

CROSSREFS

Cf. A001969, A003159 (indices of odd numbers in A234431), A131323 (odd numbers in A234431).

Sequence in context: A310281 A287365 A257336 * A310282 A081858 A145837

Adjacent sequences:  A234428 A234429 A234430 * A234432 A234433 A234434

KEYWORD

nonn,easy,base

AUTHOR

Irina Gerasimova, Dec 26 2013

STATUS

approved

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Last modified April 22 19:11 EDT 2021. Contains 343177 sequences. (Running on oeis4.)