A231628 -id:A231628 - cp's OEIS frontend

A231629 First of 7 consecutive deficient numbers in arithmetic progression.

801339, 962649, 7353339, 21964299, 41642139, 48049689, 55455939, 89034939, 89851449, 92253849, 105259539, 107948379, 109455339, 114295449, 116754939, 122349369, 135575979, 156009849, 159521049, 173645439, 188586699, 192674169, 193137849, 220301769, 221355125

Offset: 1

Shyam Sunder Gupta, Nov 11 2013

nonn

			801339, 801341, 801343, 801345, 801347, 801349, 801351 is the smallest set of 7 consecutive deficient numbers in arithmetic progression so 801339 is in the list.

Shyam Sunder Gupta, Table of n, a(n) for n = 1..126

Cf. A005100, A231623, A228964, A231624, A231625, A231626, A231628.

DefQ[n_] := DivisorSigma[1, n] < 2 n; m = 2; z1 = 2; cd = 1; a = {}; Do[If[DefQ[n], If[n - z1 == cd, m = m + 1; If[m > 6, AppendTo[a, n - 6*cd]], m = 2; cd = n - z1]; z1 = n], {n, 3, 1000000000}]; a

A231630 Smallest sets of 8 consecutive deficient numbers in arithmetic progression. The initial deficient number is listed.

Original entry on oeis.org

221355125, 221355127, 402640539, 402640541, 668862579, 668862581, 739577139, 739577141

Offset: 1

Shyam Sunder Gupta, Nov 11 2013

nonn

			221355125, 221355127, 221355129, 221355131, 221355133, 221355135, 221355137, 221355139 is the smallest set of 8 consecutive deficient numbers in arithmetic progression so 221355125 is in the list.

Cf. A005100, A231623, A228965, A231624, A231625, A231626, A231628, A231629.

DefQ[n_] := DivisorSigma[1, n] < 2 n; m = 2; z1 = 2; cd = 1; a = {}; Do[If[DefQ[n], If[n - z1 == cd, m = m + 1; If[m > 7, AppendTo[a, n - 7*cd]], m = 2; cd = n - z1]; z1 = n], {n, 3, 1000000000}]; a

cp's OEIS Frontend

A231629 First of 7 consecutive deficient numbers in arithmetic progression.

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