A131700 Sum of all n-digit Cullen numbers.

13, 90, 1443, 6658, 81923, 827395, 17956868, 157286403, 1434451971, 12884901891, 114353504259, 1005022347267, 8761733283843, 166026255794180, 1337006139375619, 11434920928870403, 97390341941886979, 1799188051134513156, 14231374822490767363, 119903836479112085507

Offset: 1

Author

Parthasarathy Nambi, Sep 15 2007

Keywords

• nonn
• base
• less

Examples

			Sum of all 1-digit Cullen numbers is 1 + 3 + 9 = 13.
Sum of all 2-digit Cullen numbers is 25 + 65 = 90.
Sum of all 3-digit Cullen numbers is 161 + 385 + 897 = 1443.
		

Links

• E.W. Weisstein, Cullen Number

Crossrefs

Cf. A002064.

Programs

Mathematica

digNum[n_] := Length @ IntegerDigits[n]; cullen[n_] := n * 2^n + 1; digCount = 0; sum = 0; cumsum = {}; Do[c = cullen[n]; If[digNum[c] > digCount, digCount++; AppendTo[cumsum, sum]]; sum += c, {n, 0, 65}]; Differences[cumsum] (* Amiram Eldar, Nov 30 2019 *)

Extensions

More terms from Amiram Eldar, Nov 30 2019